人教版高中英语选择性必修第四册UNIT 3 SEA EXPLORATION Section Ⅱ Learning About Language课件

(共68张PPT)
复习动词不定式
一、图解语法
二、观察感悟
阅读下面短文，感知加黑部分，并完成下面的练习。
As we all know，it's important ①to master a foreign language.However，Lin Tao found it difficult ②to learn English，leaving him at a loss.He was always busy and had a lot of homework given by his English teacher ③to do.There was an urgent need ④to improve his learning efficiency in order ⑤to keep up with the teacher's pace.One day，his teacher advised him ⑥to sign up for an online course，whose aim was ⑦to improve students' enthusiasm for learning and it provided useful learning methods.⑧To improve his English performance，he worked day and night，focusing on his course and practicing hard.
[我的发现]
1.以上句子中黑体部分均是动词不定式。动词不定式在句中可充当主语(如___)、宾语(如___)、宾语补足语(如___)、表语(如___)、定语(如____)及目的状语(如_____)。
2.动词不定式的一般式结构为_____。
①
②
⑥
⑦
③④
⑤⑧
to do
一、动词不定式的形式特点
动词不定式的形式是“to＋动词原形”。其否定形式为“not to ＋动词原形”。动词不定式没有人称和数的变化。
二、动词不定式的时态和语态
— 主动语态 被动语态 意义
一般式 to do to be
done 表示动作与谓语动作同时发生或发生在谓语动作之后
完成式 to have
done to have
been
done 表示动作发生在谓语动作之前
进行式 to be
doing — 表示谓语动作发生时，动词不定式的动作正在进行
1.动词不定式的一般式的主动形式为(not) to do，其被动式为(not) to be done，常表示尚未发生或者谓语动词随后发生的动作或状态。
I need to do my homework before I go out with friends，or my parents will be angry.
在我和朋友出去之前，我需要做作业，否则我的父母会生气。
The project is almost finished，and it needs to be done by tomorrow to meet the deadline.
项目快完成了，为了按时交付，需要在明天之前完工。
2.动词不定式的完成式为(not) to have done，表示动词不定式的动作发生在谓语动词之前，其被动式为(not) to have been done。
He was disappointed not to have done well in the exam.
他因考试不理想而感到失望。
The task is said to have been completed last week，but no one is sure if it was actually finished on time.
据说这项任务上周已经完成，但没有人确定它是否真的按时完成。
3.动词不定式的进行式为(not) to be doing，表示在谓语动作发生时，动词不定式的动作也正在进行。
When his mother came in，he pretended to be studying.
当他妈妈进来时，他假装在学习。
[即时演练1]　单句语法填空/完成句子
①(2025·全国一卷)As a new unit started，I asked everyone _______(write) a persuasive piece on a health-related topic of their choice.
②With a lot of work ______(do)，she will be busy in the following days.
③The task is expected _____________(complete) by the end of the day.
④(2024·全国甲卷)Although parks of all sizes and types exist at any level，the national parks，in particular，tend _______(catch) our attention because of their large size and variety.
to write
to do
to be completed
to catch
⑤我今天有很多事情要做，比如打扫房子和购物。
I _____________________ today，like cleaning the house and shopping for groceries.
⑥他假装没有做完作业，尽管他早就做完了。
He pretended ______________________________，even though he completed it earlier.
have a lot of things to do
not to have finished his homework
三、动词不定式的句法功能
动词不定式可以作主语、宾语、宾语补足语、表语、定语、状语。动词不定式强调动作的一次性、具体性。
1.作主语
动词不定式作主语通常表示具体的、一次性的动作；经常可以转换成it作形式主语的结构，动词不定式置于句后作真正的主语。
To do your best in every situation is the key to success.(主语)
在每种情况下尽力而为是成功的关键。
It is difficult to make everyone happy all the time.(it作形式主语，动词不定式作真正的主语)
一直让每个人都高兴是很困难的。
2.作宾语
其后通常跟动词不定式作宾语的动词有agree、pretend、beg、decide、expect、fail、hope、intend、manage、afford、offer、plan、promise、refuse、wish、desire、choose、determine、demand、attempt、want、aim、prepare、hesitate、long、tend等。
She decided to study abroad next year to improve her language skills.(动词不定式作宾语)
她决定明年去国外留学，以提高她的语言能力。
He planned to learn English at the age of 40.
他计划四十岁的时候开始学英语。
M,.
①不定式作动词的宾语，其后跟补语时，常用it 作形式宾语，而把不定式后置。常见的此类动词有 make、think、feel、consider。
②动词intend、mean、plan、hope、want、would like/love等后跟不定式的完成式表示“本打算做某事而实际上却没有做”。
She found it difficult to finish the project on time due to unexpected challenges.(it作形式宾语，不定式为真正的宾语)
由于出现意想不到的挑战，她发现按时完成项目很困难。
I would like to have visited the museum yesterday，but I didn't have enough time.(虚拟语气)
我本想昨天去参观博物馆的，但我没有足够的时间。
|名师点津|
3.作表语
动词不定式作表语用来说明主语的内容，常用作主语的名词有wish、plan、idea、suggestion、hope、advice、goal、aim等。
His hope is to travel abroad next summer and explore different cultures.
他的希望是明年夏天出国旅行，探索不同的文化。
4.作宾语补足语
其后常跟动词不定式作宾语补足语的动词有ask，tell，want，expect等。
We expect our team to perform well in the competition this weekend.
我们期望我们团队在这个周末的比赛中表现出色。
5.作定语
动词不定式作定语，要放在它所修饰的名词或代词后面。
She found a place to stay while she was on vacation.
在她度假期间，她找到了一个住的地方。
M,.
|名师点津|
动词不定式作定语必须后置，通常要注意以下几种情况：
①被修饰的名词或代词是动词不定式的逻辑宾语。如果动词不定式当中的动词是不及物动词且和被修饰的名词是逻辑上的被动关系时，动词不定式后应有必要的介词。
②名词或代词前有序数词修饰，其后要用动词不定式作后置定语，且被修饰的名词或代词是动词不定式的逻辑主语。
M,.
She has a house to look after while her parents are away on vacation.(不定式中的look after与a house之间为动宾关系，所以介词after不能省掉)
在父母度假期间，她需要照看房子。
As we all knew，he was the second person to arrive at the meeting yesterday.(名词前有序数词)
正如我们都知道的，他是昨天第二个到达会场的人。
|名师点津|
6.作状语
动词不定式及其短语具有副词的特性，可在句子中作目的、结果、原因状语。
①作目的状语
动词不定式作目的状语，位于句首时可以用逗号与句子隔开，位于句末时其前则不能用逗号；还可以用in order (not) to do 或 so as (not) to do来表示目的，但so as (not) to do 不能置于句首。
He saved money to buy a new laptop for school.
他省钱是为了买一台用于学习的新的笔记本电脑。
He spoke softly so as not to disturb the others during the presentation.
在演讲期间，他轻声说话以免打扰其他人。
②作结果状语
动词不定式作结果状语常用于so＋形容词/副词＋as to...“如此……以至于……”，形容词/副词＋enough to...“足够……”，too...to...“太……以至于……”；也可以表达出乎意料的结果，多置于only，never，just等词后面。
The story was so interesting as to keep everyone engaged until the end.
故事太有趣了，以至于令每个人到最后都非常专注。
The box was too heavy to lift on my own.
这个箱子太重了，我一个人无法搬起。
③作原因状语
动词不定式作原因状语通常用来修饰表示情感、心理状态、性格等的形容词，常见的这类形容词有：happy、glad、lucky、surprised、sorry、angry、anxious、ready、clever、shocked、eager、foolish 等。
I am sorry to inform you that the event has been canceled.
很抱歉告知你，活动已被取消。
The students are anxious to find out the results of the exam.
学生们急切地想知道考试的结果。
[即时演练2]　单句语法填空/完成句子
①(2025·全国一卷)Scientists are still trying __________ (determine) how harmful microplastics are—but what they do know has raised concerns.
②(2025·全国二卷)These effects aren't just short-term but have been proved to affect a teen's well-being in the years _______ (come).
③He is the first student _______ (come) and the last _______ (leave).
④I make __ a rule to read English articles every morning.
⑤(2024·浙江卷1月)However，if you're shopping for one，buying extra _________
(benefit) from price reductions doesn't make sense.
⑥昨晚我本打算和你一起去参加聚会，但那时我太忙了。
I intended ____________________________ last night，but I was too busy then.
to determine
to come
to come
to leave
it
to benefit
to have gone to the party with you
四、动词不定式前面不带to的情况
1.在固定的词组 had better/would rather之后直接跟动词原形。
You had better study hard before the test if you want to pass.
如果想及格，你最好在考试之前努力学习。
2.在使役动词 let，make，have或感官动词 see，feel，watch，notice，hear等后面作宾语补足语时，不带to。
The teacher made the students rewrite their essays after the first draft was returned.
老师让学生在第一稿被退回后重写他们的作文。
I saw her leave the house early this morning，looking very excited.
我看见她今天早上早早离开了家，看起来很兴奋。
3.在引导疑问句的why not之后。“Why not＋不带to的动词不定式？”与“Why don't you do...？”同义，用来表示提出建议或劝告。
Why not go to the park this afternoon and enjoy the sunshine
＝Why don't you go to the park this afternoon and enjoy the sunshine
今天下午你为什么不去公园，享受阳光呢？
4.动词不定式在help之后作宾语补足语时，可带to也可不带to。
He helped his sister (to) clean the room before their parents arrived.
在父母到来之前他帮助妹妹打扫房间。
[即时演练3]　完成句子/句式转换
①你可以帮我搬一下那些重的书吗？
Could you _______________________________
②对于你不了解的事情，你最好不要发表评论。
__________________________________ that you don't know at all.
③昨天我注意到他在花园里干活了。
I _______________ in the garden yesterday.
④Why not go to Hainan for our holidays
→_______________________ for our holidays
help me (to) carry those heavy books
You'd better not make remarks about things
noticed him work
Why don't we go to Hainan
五、动词不定式的特殊用法
1.疑问词 what、which、who、when、where、how 及连接词whether 可与动词不定式连用而组成一个短语，这个短语可在句中作句子的主语、宾语或表语等。
We need to decide where to hold the meeting tomorrow.
我们需要决定明天在哪里举行会议。
How to improve your English skills is a common question for many learners.
如何提高英语技能是许多学习者常问的问题。
2.只能用动词不定式作主语的句式有：
it takes/took sb ..to do sth做某事花费某人多长时间
it is up to sb to do sth 由某人决定做某事
It takes her an hour to complete her homework every day.
她每天花一个小时完成作业。
3.动词不定式用在 but、except 等后面时，如果这些词前有行为动词do的各种形式，那么后面的不定式不带to，否则要带to。即“有 do无 to”。
We have nothing to do but wait for another chance.
我们别无选择，只能等待另一个机会。
We have no choice but to cancel the trip due to the storm.
因为暴风雨，我们别无选择只能取消旅行。
4.动词不定式的主动形式表示被动含义的情况：
①动词不定式to blame 用作表语时，常用主动形式表被动意义。
She is to blame for not informing us of the change in schedule.
她应该为没有告知我们时间表的变动负责。
②某些“主语＋be＋形容词＋to do”结构中，动词不定式与主语有逻辑上的被动关系时，动词不定式可用主动形式表示被动意义。
The task is easy to complete.
这个任务很容易完成。
The job is tiring to finish.
完成这项工作很累人。
③动词不定式用于修饰“there be＋名词”中的名词时，可用主动形式，也可用被动形式，有时含义相近。
There are many questions to answer(＝to be answered)in the test.
测试中有许多问题需要回答。
[即时演练4]　单句语法填空/完成句子
①(2025·全国二卷)Volunteers are also more likely ______ (look) after their own health and are more focused on adding physical activity into their lives.
②I have no choice but ______ (go).
③何时开始尚未决定，因此需要进一步讨论。
____________ has not been decided，so a further discussion is needed.
④我们正在讨论是去山上还是去海边度过暑假。
We are debating _________________________ or to the seaside for our summer holidays.
to look
to go
When to start
whether to go to the mountains
1.profession n.职业；行业
[教材原句]　Henry Norman Bethune devoted his life and profession to helping people without expecting anything in return.亨利·诺曼·白求恩把他的生命和职业生涯都用来帮助人们，而不求任何回报。
(1)by profession　　　 职业上；就职业来说
(2)professional adj. 业的；职业的；职业性的
n. 业人员；职业运动员
(3)professionally adv. 职业地
[即时训练]　单句语法填空/完成句子
①___ profession，Maria is a doctor，but in her free time，she enjoys painting and reading novels.
②(2025·浙江卷)This platform is not only reserved for ____________(profession) cooks，but also for those willing to discover new experiences.
③作为消防员的职业让他的父亲成为当地的英雄，总是乐于为有需要的人提供帮助。
_________________________________________________，always ready to help people in need.
[写作积累]　As soon as he graduated from university，he chose teaching as his profession because he loves helping children learn and grow every day.(读后续写之人物介绍)他一毕业就选择了教学作为他的职业，因为他喜欢每天帮助孩子们学习和成长。
By
professional
His father's profession as a firefighter makes him a local hero
2.mixture n.混合；结合体；混合物
[教材原句]　Reaching out across the sea is often a mixture of danger and boredom.远渡重洋往往既危险又无聊。
(1)mix vi.& vt.　　 (使)混合；(使)结和
mix with 与……混合；融合
mix A with B＝mix A and B (together) 把A与B混合起来/融合在一起
mix up 混淆；弄混；弄乱
(2) mixed adj. 混合的；混杂的
[即时训练]　单句语法填空/完成句子
①She wore a ______ (mix) color dress，combining shades of blue，green，and yellow，which made her look unique.
②The park is a perfect ________(mix) of nature and modern facilities，offering visitors a peaceful and enjoyable environment.
③It's easy to mix __ the names of the two new students since they both look similar.
④在烤面包之前，我们需要将面粉与水混合在一起，做成面团。
__________________________ before baking the bread to make the dough.
[写作积累]　I felt a mixture of excitement and fear.My heart was racing，and my palms were sweating.(读后续写之心理描写)我既感到兴奋又感到恐惧。我的心跳加速，手掌出汗。
mixed
mixture
up
We need to mix flour with water
3.applaud vt.& vi.鼓掌 vt.称赞；赞赏
[教材原句]　The crowd stood to applaud scientists for their important ocean research work.观众起立为科学家们重要的海洋研究工作鼓掌。
(1)applaud for　　　　 为……鼓掌/喝彩
(2)applause n. 鼓掌；掌声
gain one's applause＝gain applause from sb 赢得某人的掌声
burst into applause 爆发出掌声
[即时训练]　单句语法填空/完成句子
①After his excellent presentation on the environment，John gained applause ____ the teacher.
②All her teachers and classmates applauded ___ her and there was a wide smile on her face.
③When I finished my performance，the audience burst into ________ (applaud).
④教练为球队的合作而鼓掌，团队合作让他们赢得了胜利。
___________________________________，which helped them secure the victory.(读后续写之动作描写)
[写作积累]　The audience applauded for the talented singer after her wonderful performance on stage.(读后续写之动作描写)在她精彩的舞台表演之后，观众为这位才华横溢的歌手鼓掌喝彩。
from
for
applause
The coach applauded the team's teamwork
Ⅰ.单句语法填空(每小题1.5分，共15分)
1.The movie is exciting _______ (watch).
2.__________ (give) a second chance is something many people wish for.
3.She decided _______(take) the bus to work.
4.His goal is ________ (finish) the project on time.
5.The mission is _____________(complete) by next week.
(满分：95分)
to watch
To be given
to take
to finish
to be completed
6.He was invited _______________ (interview) by the hiring manager.
7.The task is said ___________________ (complete) by the team the other day.
8.She left early _______ (catch) the first bus.
9.There are several things ___________(consider) before making a decision.
10.(2024·新课标Ⅰ卷)These sepals open on warm days _______(give) the inside plants sunshine and fresh air.
to be interviewed
to have been completed
to catch
to consider
to give
Ⅱ.语法与写作(用动词不定式完成句子)(每小题3分，共30分)
1.学习一门新语言需要大量的时间和精力。
____________________ takes a lot of time and effort.
2.她打算下周末去看望她生活在乡下的祖父母。
She _________________________ who live in the countryside next weekend.
3.他们请她帮忙准备学校节日活动。
They __________________________________ the school festival.
4.在任何团队活动中，遵守规则很重要。
In any team activity，it is important ________________.
To learn a new language
plans to visit her grandparents
asked her to help with the preparations for
to follow the rules
5.尽管她对那份工作不太感兴趣，但她别无选择，只好接受这份工作邀请。
She __________________________________，even though she wasn't very interested in it.
6.他的梦想是成为像爱因斯坦那样的著名科学家，所以他每天都努力学习数学和科学。
His dream is _________________________ like Einstein，so he works hard at math and science every day.
7.为了赶上校车，那天他早上六点就起床了。
He woke up early at 6 a.m.that day____________________.
had no choice but to accept the job offer
to become a famous scientist
to catch the school bus
8.听到最好的朋友在写作比赛中获得一等奖的好消息，他很高兴。
He was happy __________________ that his best friend had won the first prize in the writing contest.
9.春天时，这里是市里最值得参观的地方，特别适合喜欢花和安静散步的人。
This is __________________ in the city during spring，especially for those who enjoy flowers and quiet walks.
10.连续学了五个小时之后，她太累了，无法继续做作业了。
After studying for five hours without a break，she was too tired __________________
_________.
to hear the good news
the best place to visit
to continue doing her
homework
1
Ⅲ.语法与语篇(每小题1.5分，共15分)
阅读下面短文，用所给动词的适当形式填空。
Not that long ago，my first thought at mealtimes was 1.______ (eat) at a restaurant.I was eager 2.______ (try) new restaurants.To eat out was also a social activity，allowing me 3._________ (enhance) the relationship with my friends.I often ate out until last month，when I came across a cooking app.There are a variety of recipes in the app 4._________ (choose) from.They are uploaded by users，and offer detailed instructions for others 5.__
_____ (follow) step by step.Most of the recipes include photos or videos，which are very useful for beginners.When I picked a popular recipe and gave it a try，I discovered that it
to eat
to try
to enhance
to choose
follow
to
was not that difficult 6._______ (make) a simple and tasty dish.In the past few weeks，I've thrown myself into home cooking，from boiling noodles in the pot to 7.______ (fry) steak in the pan.I hardly eat out any more.Not only is cooking at home cheaper，but I can cook exactly what I want.It's healthier too.No wonder people say nothing beats home cooking!
Now I am good at 8._______ (cook) a couple of dishes.My plan is 9.________ (invite) my friends over at the weekend 10._______ (show) them my new-found skills.I hope that they will like my cooking!
to make
frying
cooking
to invite
to show
Ⅰ.阅读理解(每小题2.5分，共20分)
A
With needle-like teeth and sharp pointed nose，a gray nurse shark isn't a creature that most people would want to meet.But Shalise Leesfield isn't one of them.
The Australian teenager couldn't think of a better creature to meet when scuba diving off the coast of South West Rocks，near her home in Port Macquarie，a coastal town north of Sydney.
“Many people say gray nurse sharks look frightening，but I think they are the sweetest animals ever，” she says.
The slow-moving sharks，which like to stay near the sea floor in warm，shallow waters，are—for the most part—harmless to humans.But the gray nurse shark is under threat.Populations have fallen and habitats have been lost due to ocean warming and human development，according to the International Union for Conservation of Nature (IUCN)，which lists the species as seriously endangered.
One area where they can still be seen is Fish Rock，an underwater cavern (洞穴) with a unique ecosystem，40 miles up the coast from Leesfield's home.But fishers are allowed access within 200 meters of Fish Rock.This is leading to a drop in the number of gray nurse sharks and increased pollution，says Leesfield.She wants to enlarge the no-fishing area，establishing a protected zone.
With Leesfield's efforts，the area has been nominated as a Hope Spot，which is part of the mission Blue program launched by famous oceanographer Sylvia Earle that identifies places as critically important to the ocean's health and supports protection.
“When people think about Hope Spots，they think about Sydney Harbour or the Great Barrier Reef.So to get Fish Rock up on that list is just such incredible news，” she says.
Now，Leesfield is working with politician Cate Faehrmann，marine spokesperson for the Australian Greens party in New South Wales，to legalize protection of the sharks and make the no-fishing zone protected by the law.
[语篇解读]　本文是一篇记叙文。文章讲述澳大利亚少年Shalise Leesfield致力于保护沙锥齿鲨的故事。
1.What does “them” refer to in the first paragraph
A.Gray nurse sharks.
B.Common people.
C.People fearing gray nurse sharks.
D.Fishers.
解析　C　代词指代题。由第一段内容和第三段内容可知，大多数人因害怕都不想见到沙锥齿鲨，但Shalise Leesfield喜欢沙锥齿鲨，说明Shalise Leesfield不是害怕沙锥齿鲨的人，them指代“害怕沙锥齿鲨的人”。故选C。
2.What has led to gray nurse sharks' being seriously endangered
A.The development of tourism in the ocean.
B.The sharks' preference to stay in shallow waters.
C.The feature of gray nurse sharks' slow-moving.
D.Fishers' being permitted within 200 meters of Fish Rock.
解析　D　推理判断题。由第四段中“But the gray nurse shark...seriously endangered.”和第五段中“But fishers are allowed...says Leesfield.”可知，因人类活动，渔民被允许靠近Fish Rock 200米范围内捕鱼导致沙锥齿鲨受到严重威胁。故选D。
3.What will Leesfield and Faehrmann do to protect gray nurse sharks
A.Recommend the Fish Rock as a Hope Spot being protected.
B.Identify the Hope Spot area as being critically important.
C.Make Fish Rock more popular among fishers nearby.
D.Make laws to protect the no-fishing zone near Fish Rock.
解析　D　细节理解题。由最后一段“Now...the no-fishing zone protected by the law.”可知，Leesfield和Faehrmann通过制定法律保护Fish Reck附近的禁渔区。故选D。
4.Which might be the best title for the article
A.The Australian teenager is on a mission to protect sharks
B.Increased pollution leads to gray sharks endangered
C.Gray nurse sharks are in danger!
D.Let's establish a protected zone!
解析　A　标题归纳题。通读全文可知，本文主要讲述了澳大利亚少年Shalise Leesfield致力于保护gray nurse sharks (沙锥齿鲨)的故事，A项为本文最佳标题。故选A。
B
The Greenland shark are hard to find，which primarily live in the deep，cold waters of the North Atlantic and Arctic oceans，and are the only sharks to stand the freezing temperatures year-round.Some individuals of the species might have been swimming there since colonial times—and researchers are just beginning to figure out how.
Research published in 2016 determined the sharks are the longest-living vertebrates (脊柱动物)，likely living to be around 400 years old，with the estimate ranging from 272 years old to over 500 years old.Now，a new study aims to understand the mechanism behind that longevity.
An international team of scientists has become the first to map the Greenland shark's genome (基因组)，sequencing about 92% of its DNA and providing insight into the inner workings of the long-lived fish.
The study found the shark's genome to be extraordinarily large，twice as long as a human's and bigger than any other shark genome sequenced to date.The researchers are analyzing the genome to explore what its large size may mean for the shark's longevity.One reason for a longer genome might come down to the shark's ability to repair its DNA，a feature that has commonly been seen in other species with exceptional lifespans.
The Greenland shark is unique in that a vast amount—more than 70%—of its genome is made up of jumping genes.It seems that in the Greenland shark，the genes that repair DNA have been acting as jumping genes，duplicating (复制) themselves in the genome and slowing down the aging process by fixing damaged DNA.
The study authors released their findings as a preprint—a scientific paper that has not gone through the peer-review process—as they invite more scientists to study the genome and conduct their own analysis of the shark's DNA.
By studying the longevity mechanisms of the Greenland shark，scientists could also gain more insight into how to potentially extend the human lifespan，the authors said.
[语篇解读]　本文是一篇说明文。文章主要介绍了对格陵兰鲨的研究，包括其长寿的机制和基因组的特点。
5.What can we learn about Greenland sharks in paragraph 1
A.They are known for their large size.
B.They can survive in extreme environments.
C.They are often found in warm tropical waters.
D.They have been studied extensively for decades.
解析　B　细节理解题。根据第一段“The Greenland shark...the freezing temperatures year-round.”可知，格陵兰鲨能在极端环境中生存。故选B。
6.What does the new study aim to explore about the Greenland Shark
A.How long they can actually live.
B.How they interact with other species.
C.What structures make them adaptable.
D.What contributes to their long lifespan.
解析　D　推理判断题。根据第二段“Now，a new study aims to understand the mechanism behind that longevity.”可知，这项新研究旨在探索格陵兰鲨长寿的原因。故选D。
7.What role does the large size of the Greenland shark's genome play
A.It increases their reproductive rate.
B.It allows for faster swimming speed.
C.It enhances their ability to repair DNA.
D.It makes them resistant to most diseases.
解析　C　细节理解题。根据第四段“One reason for a longer genome might come down to the shark's ability to repair its DNA.”可知，格陵兰鲨庞大的基因组增强了它们修复DNA的能力。故选C。
8.What do we know about the study
A.It has invited serious criticism.
B.It has gained wide recognition.
C.It still needs further research.
D.It solved the mystery of aging.
解析　C　推理判断题。根据倒数第二段“The study authors...their own analysis of the shark's DNA.”可推知，这项研究还需要进一步的研究。故选C。
Ⅱ.完形填空(每小题1分，共15分)
I've been interested in diving.I wanted to experience it but was 1 by the fear of deep water.Last year，encouraged by a diving enthusiast，I decided to 2 my fear.I signed up for a diving course.
After a few days of theory sessions，I surprisingly 3 all the theory exams.But then followed the biggest 4 .I was visibly 5 underwater.My instructor asked me to do a few more dives with him to 6 my confidence.However，I could see a huge 7 between what I thought I'd be doing and what the course 8 required.
Over the next few weeks，I looked back on the past and thought about what I could have done differently to have had a more pleasant 9 .It was a 10 game! If I could win，I would be able to 11 this course.
A week before the end of the diving course，I went to complete two dives with my instructor.I knew that if I didn't give it another 12 ，I would always carry the fear with me，and it would only get 13 with time.As I revised the 14 and put on my gear (装备)，I thought to myself，“This is it！” I took a deep breath，held my mask in place with my fingers，and did a back roll into the sea.
Three hours later，I became a 15 diver.I finally overcame my fear!
[语篇解读]　 本文是一篇记叙文，文章讲述了作者对潜水感兴趣但因为对深水的恐惧而犹豫，最终在一位潜水爱好者的鼓励下，决定克服恐惧参加潜水课程的经历。
1.A.picked out B.settled down
C.held back D.brought up
解析　C　根据下文“by the fear of deep water”，可知恐惧阻碍了作者体验潜水。hold back“阻碍”。故选C。
2.A.overcome B.hide
C.ignore D.share
解析　A　根据上文“I wanted to experience it but was _______ by the fear of deep water.”、“encouraged by a diving enthusiast”以及下文“I signed up for a diving course.”可知作者决定克服恐惧，报了一个潜水课程。故选A。
3.A.failed B.avoided
C.cleared D.assessed
解析　C　根据上文“After a few days of theory sessions，I surprisingly”以及下文“But then followed the biggest _______”可知，作者通过了所有的理论考试。故选C。
4.A.gift B.challenge
C.promise D.surprise
解析　B　根据上文“But then followed”以及下文“My instructor asked me to do a few more dives with him to _______ my confidence.”描述的困难，可知此处表示接下来是最大的挑战，故选B。
5.A.terrified B.rude
C.ashamed D.angry
解析　A　根据上文“I've been interested in diving.I wanted to experience it but was by the fear of deep water.”，可知这里表示作者在水下感到恐惧，故选A。
6.A.show B.build
C.shake D.cover
解析　B　根据下文“my confidence”，可知教练让作者多潜水几次以建立信心，故选B。
7.A.mismatch B.solution
C.connection D.wonder
解析　A　根据下文“between what I thought I'd be doing and what the course required”，可知作者意识到自己的预期与课程要求之间的不匹配，故选A。
8.A.secretly B.accidentally
C.directly D.actually
解析　D　根据下文“required”，可知，这里强调课程的实际要求，故选D。
9.A.holiday B.discussion
C.suggestion D.experience
解析　D　根据上文“My instructor asked me to do a few more dives with him to my confidence.”提到了潜水课程的经历，可知这里表示作者思考如何让经历更愉快，故选D。
10.A.card B.mind
C.health D.word
解析　B　根据下文“If I could win，I would be able to _______ this course.”以及上文提到自己对深水的恐惧，可知作者与自己的恐惧作斗争，这是一场心理游戏，故选B。
11.A.write down B.seek for
C.sail through D.check on
解析　C　根据下文“this course”，可知作者希望能够顺利通过课程，故选C。
12.A.item B.try
C.name D.record
解析　B　根据上文“give it another”，以及下文“I would always carry the fear with me”可知这里表示如果不让自己再尝试一次，自己将永远带着恐惧。故选B。
13.A.worse B.longer
C.less D.darker
解析　A　根据上文“I would always carry the fear with me”和下文“with time”，可知随着时间的推移恐惧会变得更糟，故选A。
14.A.innovations B.comments
C.fundamentals D.choices
解析　C　根据空前“As I revised the”以及上文“After a few days of theory sessions”可知这里表示复习潜水的基础知识，故选C。
15.A.highly-paid B.competitive
C.well-known D.qualified
解析　D　根据下文“I finally overcame my fear！”，可知作者最终克服恐惧，完成潜水课程，成为一名合格的潜水员，故选D。