外研版（2019）选择性必修第一册Unit 5 Revealing nature Grammar课件(共18张PPT)

(共18张PPT)
Unit 5 Revealing nature
Period 3 Using language 1 Grammar
To discover and master the concept, characteristics and usage of “past perfect tense”.
To be able to use it flexibly in real contexts.
Learning objectives
Activity 1 Look at the sentences from the reading passage and answer the questions.(P53)
a Darwin suspected that the finches had evolved from a common ancestor,...
b Many people refused to believe that living things, including humans, had evolved from lower forms of life.
1 In sentence (a), which action happened first, “suspected” or
“evolved from a common ancestor”
“Evolved from a common ancestor.”
2. In sentence (b), which action happened first, “refused to believe”
or “evolved from lower forms of life”
“Evolved from lower forms of life.”
3. What does the structure had done indicate
It indicates the action happened before a certain past action.
Now look for more sentences with the past perfect tense in the reading passage, and summarise its use in your own words.
1. It was a young man who _______ medical school without completing his degree. What’s more, he ___________________ a letter from his father predicting that he would be “a disgrace to yourself and all your family”.
had left
had recently received
2. After Darwin _________ some time in South America, his room on the
ship was crowded with samples of the plants and animals he _____________.
had spent
had collected
3. At that time, people believed that all species ____________ on Earth at the
same time, and _______________ since.
had appeared
had not changed
4. It seemed their beaks __________ according to what food was available
on that particular island.
had evolved
1) 表示在过去的某一时间或某一动作之前完成的动作或存在的状态，即“过去的过去”。
过去完成时的基本用法：
a.我们到达火车站之前，火车就已经离开了。
Before we got to the train station, the train _______________.
b.我还没来得及说谢谢，他就跑开了。
Before I could say “thank you”, he _______________.
had run away
had already left
past perfect
2) 表示从过去某一时间开始，一直延续到过去的另一个时间的动作，常用的时间状语有 by then, by the end of, by the time。
a.到上学期期末为止，我们已经学习了2000个英语单词了。
By the end of last term, we _________ 2000 English words.
b.到那时为止，他们已经在那里住了十年了。
They _________ there for ten years by then.
had lived
had learnt
3) 表示愿望、打算等的动词，如 hope, want, expect, think, mean,
suppose, intend, plan 等后接从句时，一般用过去完成时表示本
打算实现而未实现的愿望和计划。
a.我本打算去机场接他，但是我有个重要的会议要参加。
I ____________ to meet him at the airport, but I had an important
meeting to attend.
b.我原希望今年去度假，可是我离不开。
I _________ to take a holiday this year but I was not able to get away.
had intended
had hoped
4) 在句型 hardly... when 和 no sooner… than 中，主句用过去完成时，从句用一般过去时，表示“一……就……”。
a.我刚离开就开始下雨了。
______________ when it began to rain.
b.他刚坐下，电话铃就响了。
No sooner ______________ than the telephone rang.
Hardly had I left
had he sat down
Activity 2 Complete the paragraphs with the information from the given sentences. The sentences are in the order in which they happened. They can help you to decide the use of tenses.(P53)
1. a Natural disasters led to food shortages in the 1960s.
b Yuan Longping began to do research on hybrid rice.
c Yuan Longping developed a better type of rice.
Yuan Longping 1_____ to do research on hybrid rice because natural disasters 2__________ food shortages in the 1960s. In the end, he 3_________ a better type of rice.
developed
began
had led to
2. a Gregor Mendel chose to study pea plants because their
characteristics were easy to control.
b Gregor Mendel made important discoveries about genetics.
c Gregor Mendel died in 1884.
Gregor Mendel 4________ study pea plants because their characteristics were easy to control. By the time of his death in 1884, he 5__________ important discoveries about genetics.
chose to
had made
A short introduction to Yuan Longping
Yuan Longping (1930 – 2021) dedicated himself to the research of agriculture after he graduated from university in the early 1950s. Yuan had the idea to create a new breed of rice in the 1960s. Since then, he has worked tirelessly to research and develop a better rice breed. In 1973 he and his collaborators managed to cultivate a hybrid rice species that was superior to many others. This species produced 20 per cent more rice per plant than the commonly grown varieties. For his achievements and contributions, Yuan is known as the “father of hybrid rice” and was awarded the Medal of the Republic in 2019.
Yuan Longping
A short introduction to Gregor Mendel
Gregor Mendel (1822 –1884) was an influential botanist. Mendel worked out the basic principles of heredity by experimenting with plants. In 1866, he published his findings, showing how invisible “factors” (now known as genes) are responsible for predictable visible traits. As a result of his work, he became known as the “father of modern genetics”.
Gregor Mendel
Activity 3 Complete the online encyclopaedia entry with the correct form of the words in the box.(P53)
compete decline eat
live introduce arrive
Lonesome George was the last Pinta Island tortoise. He died in 2012. After George’s death, the Pinta Island tortoise was declared extinct.
The extinction of the Pinta Island tortoise is blamed on humans. Before humans 1________ on the island, the species 2_________ in isolation and 3______ the plants that naturally grew there. George was discovered many years after their arrival, and by then humans 4_______________ new species that 5__________ for the food the tortoises ate. After goats in particular had been brought to the island, the Pinta Island tortoise population 6________. Eventually, only George remained.
arrived
had lived
eaten
had introduced
competed
declined
compete decline eat live introduce arrive
Pair work
Activity 4 Act out a role-play using the information in the encyclopaedia entry. Try to use the Past Perfect Tense.
Situation 2:
You play the keeper of Lonesome George.
Use past perfect tense where appropriate
Situation 1:
You play the reporter asking about George.