基础过关1
音频2501.1
第一部分听力(共两节。满分30分)
第一节(共5小题；每小题l．5分，满分7．5分)
听下面5段对话。每段对话后有一个小题，从题中所给的A、B、C三个选项中选出最佳选项，并标在试卷的相应位置。听完每段对话后，你都有l0秒钟的时间来回答有关小题和阅读下一小题。每段对话仅读一遍。
1．What kind of news are the speakers talking about
A. Travel news B. Health news C. Sports news.
2．What sports does the child like most
A. Basketball. B. Football C. Volleyball
3．What does the man advise the woman to do
A. Do yoga． B. Eat more. C. Do more running.
4．What does the man do now
A. He exercises less often. B. He spends less time traveling.
C. He uses his computer much less.
5．What was the score of George’s game last night
A. 2-1 B. 0-0 C. 3-2
第二节(共15小题；每小题l．5分，满分22．5分)
听下面5段对话或独白。每段对话或独自后有几个小题，从题中所给的A、B、C三个选项中选出最佳选项，并标在试卷的相应位置。听每段对话或独白前，你将有时间阅读各个小题，每小题5秒钟；听完后，各小题将给出5秒钟的作答时间。每段对话或独自读两遍。
听第6段材料。回答第6，7题。
What does the woman see out of the window
A boat race. B. A soccer game. C. A crowd of people.
Which sport the man like most
A. Baseball. B. Basketball. C. Soccer.
听第7段材料。回答第8,9题。
8. What class will be taught this week
A. Weapon． B. History C. Law
9. What kind of fitness training will the speakers do
A. Lifting weights． B. Sit-ups. C. Running.
昕第8段材料。回答第l0至12题。
Why were the speakers glad
A. Their team won the game. B. They appeared in the TV news.
C. They played football that afternoon.
11. How didi the man feel at the news at first
A. Doubtful. B. Excited C. Sad.
12. Where will the speakers go next
A . To a bar. B. To their school. C. To a stadium,.
听第9段材料。回答第l3至16题。
What size skates should be worn while ice skating
The same size as regular shoes. B. One half size larger than regular shoes. C. One half size smaller than regular shoes.
What night is it tonight
A. The dance night. B. The experts’ night. C.The beginners’ night.
15. How much does the ticket cost tonight
A. ＄5. B. ＄10. C. ＄20.
16. What does the woman imply about ice skating
A . She used to love it. B. She’s excited to try it.
She doesn’t like it at all.
听第l0段材料，回答第l7至20题。
17. What does the speaker think of the players in the race
A. Brave and serious. B. Friendly and helpful. C. Strong and skillful.
18. What is needed to cross a lake
A. A big boat. B. Teamwork. C. A guide book.
19. What does the forest look like
A. It's very dark. B. It's covered with snow. C. It's easy to get through.
20. How can the players win the race
A. By getting down the mountain first.
B. By reaching the top of the mountain.
C. By planting a flag on the mountain top.
提升训练1-1
音频2501.1a
第一节 (共5小题；每小题1分，满分5分)
听下面5段对话。每段对话后有一个小题，从题中所给的A、B、C三个选项中选出最佳选项，并标在试卷的相应位置。听完每段对话后，你都有10秒钟的时间来回答有关小题和阅读下一小题，每段对话仅读一遍。
1 .Where is the woman going with her children？
A. To Australia. B. To Canada. C. To Japan.
2 .How much should the man pay？
A.＄16. B.＄32. C.＄60.
3 .What does the woman expect the man to do on Saturday？
A. Celebrate their mum’s birthday.
B. Take Brian out for the day.
C. Help Brian move house.
4 .What does the woman mean？
A. She don’t like the job.
B.She will take the job right away.
C.She isn’t sure whether to take the job.
5 .What are the speakers mainly talking about？
A. A novel. B. A film. C. A writer.
第二节（共15小题；每小题1.5分，满分22.5分）
听下面5段对话或独白。每段对话或独白后有几个小题，从题中所给的A、B、C三个选项中选出最佳选项，并标在试卷的相应位置。听每段对话或独白前，你将有时间阅读各个小题，每小题5秒钟；听完后，各小题将给出5秒钟的作答时间。每段对话或独白读两遍。
听第6段材料，回答第6、7题。
6 .What will the woman do this evening？
A. Attend a party. B. Visit her grandma. C. do some shopping.
7 .What does the man advise the woman to do？
A. Make a skirt. B. Buy a handbag. C. Wear a necklace.
听第7段材料，回答第8、9题。
8 .Where does the conversation take place？
A. At a hotel. B. At an airport. C. At a police station.
9 .What does the man suggest the woman do？
A. Wait where she is. B. Make a request for the loss.
C. Give him her telephone number.
听第8段材料，回答第10至12题。
10.What’s the relation between the speakers？
A. Husband and wife. B. Friends. C. Boss and worker.
11.Why does the woman look worried？
A .She has been late for-work recently.
B .She is not getting on well with her boss.
C .She has trouble taking her children to school.
12.What might the woman think of Alice’s way to deal with her problem？
A. Practical. B. Strange. C. Wrong.
听第9段材料，回答第13至16题。
13. How long will the course run this year
A. Six weeks. B. Seven weeks. C. Eight weeks.
14.What was the woman surprised at？
A. The lack of assistants. B. The condition of weather. C. The number of children
15. What new activities can the children have this year
A. Adventure sports. B. Fun programmes. C. Creative classes.
16. What is expected about the course this year
A. It will run better. B. It will last longer. C. It will start earlier.
听第10段材料，回答第17至20题。
17.What difficulty did the speaker have when starting to learn French？
A. Grammar. B. Vocabulary. C. Pronunciation.
18.Why did the speaker go to France？
A. To settle there. B. To look for a job. C. To continue her studies
19.What did the speaker think of her French after she arrived in France？
A. Poor. B. Acceptable. C. Excellent.
20. What is the most important in learning a language according to the speaker
A. Mastering the grammar rules.
B. Using the language in real life.
C. Knowing a large number of words.
提升训练1-2
音频2501.1b
第一节（共5小题；每小题1.5分，满分7.5分）
听下面5段对话。每段对话后有一个小题，从题中所给的A,B,C三个选项中选出最佳选项，并标在试卷的相应位置。听完每段对话后，你都有10秒钟的时间来回答有关小题和阅读下一小题。每段对话仅读一遍。
1．Where are they most probably talking？
A. In a phone box. B. In the office. C. At home.
2．What does the man want to do？
A. To get a camera. B. To buy batteries. C. To go to the cinema.
3．When will the man go to the cinema？
A. On Sunday morning. B. On Sunday afternoon. C. On Sunday evening.
4．What do you know from the man’s replies？
A. He lost Lily’s book.
B. He was badly pressed with his work.
C. He was sure that the book could be found.
5．What does the man like to collect？
A. Coins. B. Magazines. C. Paintings.
第二节（共15小题；每小题1. 5分，满分22.5分）
听下面5段对话或独白。每段对话或独白后有几个小题，从题中所给的A,B,C三个选项中选出最佳选项，并标在试卷的相应位置。听每段对话或独白前，你将有时间阅读各小题，每小题5秒钟；听完后，各小题将给出5秒钟的作答时间。每段对话或独白读两遍。
听第6段材料，回答第6至8题。
6．Who was ill last week
A. Mr. Hudson. B. Mr. Hudson’s mother. C. Mr. Hudson’s son.
7．What kind of person is Mr. Hudson according to the dialogue？
A. A very good worker.
B. A person who often gets angry.
C. A person who cares nothing.
8．Which may be the reason why Mr. Hudson is so sad？
A. His problem at work.
B. His son has brought him some trouble.
C. His manager wants to fire him.
听第7段材料，回答第9至11题。
9．Where does the conversation probably take place？
A. At home. B. At the doctor’s. C. At the restaurant.
10．Why does the man feel stressful？
A. He struck his head on a cupboard door.
B. He found it difficult to sleep．
C. He is going to attend an important examination.
11．How did the woman deal with the problem of the man
A. She did nothing.
B. She gave him some suggestions.
C. She advised him to come back again.
听第8段材料，回答第12至14题。
12．Where does Mike work？
A. In a grocery. B. In a language school. C. In an art school.
13．What does the woman want to do for a change？
A. Learn to dance. B. Learn to sing. C. Learn to paint.
14．What is most difficult for the woman about learning Arabic？
A. Grammar. B. Pronunciation. C. Idioms.
听第9段材料，回答第15至17题。
15．What is Mr. Li’s class about？
A. How to learn English well.
B. How to prepare for a speech.
C. How to get ready for an interview.
16．What is the most important thing in an interview？
A. Friendliness. B. Honesty. C. Quickness.
17．Where are they speaking？
A. On the phone. B. In the street. C. In the classroom.
听第10段材料，回答第18至20题。
18．What will be held in the Twin Cities in 2015？
A. Winter Olympics. B. Summer Olympics. C. Senior Olympics.
19．How long will the game last
A. Seven days. B. Fourteen days. C. Eighteen days.
20．How often is the event held？
A. Every two years. B. Every four years. C. Every five years.
提升训练1-3
音频2501.1c
第一节（共5小题；每小题1.5分，满分7.5分）
听下面5段对话。每段对话后有一个小题，从题中所给的A、B、C三个选项中选出最佳选项，并标在试卷的相应位置。听完每段对话后，你都有10秒钟的时间来回答有关小题和阅读下一小题。每段对话仅读一遍。
1. What will the woman do on Sunday
A. Go to Canada. B. Have dinner with the man. C. Go to the man’s house.
2. Which club is the man in
A. The sports club. B. The performance club. C. The book club.
3. How many people will attend the meeting now
A. 15. B. 35. C. 50.
4. Why did the man leave Atlantic Industrial
A. He likes marketing. B. He found the job boring. C. The job was unrelated with electronics.
5. What do we know about the man
A. He missed the meeting at the university.
B. He feels strange about losing his way.
C. He has never been to the university before.
第二节（共15小题；每小题1. 5分，满分22.5分）
听下面5段对话或独白。每段对话或独白后有几个小题，从题中所给的A、B、C三个选项中选出最佳选项，并标在试卷的相应位置。听每段对话或独白前，你将有时间阅读各个小题，每小题5秒钟；听完后，各个小题将给出5秒钟的作答时间。每段对话或独白读两遍。
听第6段材料，回答第6至8题。
6. Which bus goes to River Drive
A. No.16. B. No.14. C. No.6.
7. What will the woman ask the bus driver
A. Where to change buses. B. The ticket price. C. How to get some change.
8. What’s the relationship between the speakers
A. Friends. B. Driver and passenger. C. Strangers.
听第7段材料，回答第9至11题。
9. Where does this conversation probably take place
A. On a plane. B. At the airport. C. At a restaurant.
10. Why does the man complain
A. He can’t sit next to his wife.
B. He can’t get a business-class ticket.
C. There are no tickets available.
11. Where will the man and his wife sit
A. In business class. B. In economy class. C. One in 38-G and one in 44- A.
听第8段材料，回答第12至14题。
12. How does Steven spell the word
A. P-E-T-P-E-I-V-E. B. P-E-T-P-E-E-V-E. C. P-I-T-P-E-E-V-E.
13. Why does the woman talk about watching a movie
A. To tell the man her experience.
B. To explain something.
C. To express her feelings.
14. What did the woman’s mother ask her to do last Friday
A. Do some shopping. B. Help her with cooking. C. Watch TV.
听第9段材料，回答第15至17题。
15. Where might the speakers be
A. On a street. B. In a library. C. At home.
16. What does the man think of seeing-eye dogs
A. They cost too much.
B. They aren’t as useful as we expect.
C. They are hard to get.
17. What can we learn from the conversation
A. The woman is blind.
B. The man’s fingers are very sensitive.
C. They are willing to help the disabled.
听第10段材料，回答第18至20题。
18. How long is the route
A. About 170 kilometers. B. About 700 kilometers. C. About 1700 kilometers.
19. What did the brave Alaskans bring to Nome in 1925
A. Medicine. B. Food. C. Gold.
20. What do most of the drivers consider to be a victory
A. Winning the race. B. Finding gold. C. Finishing the race.
基础过关2
音频2501.2
第一部分听力(共两节。满分30分)
第一节(共5小题；每小题l．5分，满分7．5分)
听下面5段对话。每段对话后有一个小题，从题中所给的A、B、C三个选项中选出最佳选项，并标在试卷的相应位置。听完每段对话后，你都有l0秒钟的时间来回答有关小题和阅读下一小题。每段对话仅读一遍。
How much does the woman have
A. $30. B. $40. C. $ 50.
2. What does the woman think of the literature class
A. Helpful. B. Tiring. C. Confusing.
3. What are the two speakers talking about
A. A travel plan. B. A big company. C. A job opportunity.
4. What does the man mean
A. The woman is lazy. B. The woman is helpful,
C. The woman should refuse John.
5. What are the speakers looking at
A. A picture. B. A rainbow. C. A light show.
.第二节(共15小题；每小题l．5分，满分22．5分)
听下面5段对话或独白。每段对话或独自后有几个小题，从题中所给的A、B、C三个选项中选出最佳选项，并标在试卷的相应位置。听每段对话或独白前，你将有时间阅读各个小题，每小题5秒钟；听完后，各小题将给出5秒钟的作答时间。每段对话或独自读两遍。
听第6段材料。回答第6，7题。
6. What does the woman bring the man
A. A cup of milk. B. A cup of coffee. C.A glass of red wine.
7. What does the man order
A. Pan-fried catfish. B. Potatoes and salad. C. A medium-rare steak.
听第7段材料。回答第8,9题。
What is the woman's favorite thing to buy at the market
A. Electronics. B. Food. C. Clothes.
9. When will the speakers go to the market
A. Tomorrow. B. This weekend. C. Next month.
听第8段材料。回答第l0至12题。
10. What did the woman just do
A. She bought a dress. B. She worked in the garden.
C. She helped her mother wash clothes.
11. What does the man say about the woman
A. She has a talent for gardening. B. Her fingers will turn green soon.
C. She knows a lot about the British royal family.
12. When does the woman probably help her mother
A. Every morning. B. Every afternoon. C. Every evening.
.听第9段材料。回答第l3至16题。
When did the speakers go to watch the game
A. On Sunday. B. On Friday. C. On Saturday
What did the boy say he hoped to do
A. Be a soccer coach B. Be on the national team. C. Play in the next World Cup.
15. How old is the boy
A.14 years old. B.15 years old. C. 18 years old.
16. What teams were probably playing in the game
A. Brazil and England. B. America and England. C. Portugal and Brazil.
听第l0段材料，回答第l7至20题。
Who usually takes a year off before college :
A. The Australian students. B. The American students. C. The African students.
18. Why do some students take a year off after high school
A. To travel or work. B. To earn some school fees.
C. To get into a good university.
19. What is the legal drinking age in the United States
A.18 years old. B.19 years old. C. 21years old.
What is the speaker's main opinion
A. More American students should take a gap year.
Americans are more prepared than Europeans.
The travel experience is not important.
提升训练2-1
音频2501.2a
第一节（共5小题；每小题1.5分，满分7.5分）
听下面5段对话。每段对话后有一个小题，从题中所给的A、B、C三个选项中选出最佳选项，并标在试卷的相应位置。听完每段对话后，你都有10秒钟的时间来回答有关小题和阅读下一小题。每段对话仅读一遍。
1.What is the man
A.A taxi driver. B.A policeman. C.A restaurant waiter.
2.When will the man fly back
A.Next week. B.On Sunday. C.Before this weekend.
3.How does the woman feel
A.Discouraged. B.Satisfied. C.Delighted.
4.How many bank robbers were there altogether
A.One. B.Two. C.Four.
5.What would the man probably do
A.To save 300. B.To repair the car. C.To buy a new car.
第二节（共15小题；每小题1. 5分，满分22.5分）
听下面5段对话或独白。每段对话或独白后有几个小题，从题中所给的A、B、C三个选项中选出最佳选项，并标在试卷的相应位置。听每段对话或独白前，你将有时间阅读各个小题，每小题5秒钟;听完后，各小题将给出5秒钟的作答时间。每段对话或独白读两遍。
听第6段材料，回答第6至8题。
6.What are the speakers doing
A.Cooking. B.Working. C.Having dinner.
7.What happened to the man’s finger
A.It’s cut. B.It’s burnt. C.It’s wounded.
8.What was put on the man’s finger
A.The ice. B.The bandage. C.The cream.
听第7段材料，回答第9至11题。
9.How much does the apartment near a park cost
A. 350. B. 390. C. 400.
10.What do we know about the one near University Avenue
A.It’s most expensive. B.It’s too large. C.It’s noisy.
11.What do we know about Metealfe
A.It’s near a university. B.It’s a quiet street. C.It’s near a park.
听第8段材料，回答第12至14题。
12.Who is the woman
A.She is a car park attendant.
B.She is a policewoman.
C.She is a driver whose car is being blocked by the man’s car.
13.Why didn’t the man park his car in the car park around the corner
A.He didn’t know there was a car park around the corner.
B.He didn’t want to pay for the parking.
C.He thought it would be full.
14.What will the man probably do next
A.He is going to the police station.
B.He will show the woman his license.
C.He is driving away.
听第9段材料，回答第15至17题。
15.When does the conversation probably take place
A.In the morning. B.At noon. C.In the afternoon.
16.Where did the woman go first
A.The police station. B.A restaurant. C.A shop.
17.Who does the man suggest the woman phone
A.The woman’s friend.
B.The manager of the shop.
C.The manager of the restaurant.
听第10段材料，回答第18至20题。
18.What is the aim of the pro gram
A.To keep the trainees in shape.
B.To improve public relations.
C.To develop leadership skills.
19.How long will the program last in July
A.8 days. B.12 days. C.20 days.
20.If people want to join the program,what should they do after the meeting
A.Ta ke a pre?text. B.Pay for the program. C.Sign on a piece o f paper.
提升训练2-2
音频2501.2b
第一节（共5小题；每小题1.5分，满分7.5分）
听下面5段对话。每段对话后有一个小题，从题中所给的A, B, C三个选项中选出最佳选项，并标在试卷的相应位置。听完每段对话后，你都有10秒钟的时间来回答有关小题和阅读下一小题。每段对话仅读一遍。
1. What does the woman need to do this weekend
A. To get her car fixed.
B. To do her homework.
C. To meet a friend.
2. What will the woman buy for the man？
A. Oranges and bananas.
B. Apples and oranges.
C. Grapes and oranges.
3. What does the man mean
A. The exam seems to be easier than it first appeared.
B. He thinks they made the exam difficult on purpose.
C. The exam is more difficult than he thought.
4. What is the woman
A. A waitress. B. A doctor. C. A teacher.
5. What will the woman take
A. A taxi. B. A bus. C. The underground.
第二节（共15小题；每小题1.5分，满分22.5分）
听下面5段对话或独白。每段对话或独白后有几个小题，从题中所给的A, B, C三个选项中选出最佳选项，并标在试卷的相应位置。听每段对话或独白前，你将有时间阅读各个小题，每小题5秒钟；听完后，各小题将给出5秒钟的作答时间。每段对话或独白读两遍。
听第6段材料，回答第6至第8题。
6. What is the main topic of the conversation
A. City life. B. Life abroad. C. The climate in California.
7. What does the man think of the people in the city
A. Friendly. B. Hardworking. C. Humorous.
8. Where does the man come from
A. Japan. B. Canada. C. Britain.
听第7段材料，回答第9至第11题。
9. What is the probable relationship between the two speakers
A. Workmates. B. Boss and secretary. C. Manager and job hunter.
10. Why did the woman fail to get the job according to the man
A. She is a woman. B. She is improperly dressed. C. She is not fit for the position.
11. What can we learn from the conversation
A. Carl White is a good manager.
B. The man thinks the woman is too proud.
C. The woman thinks ability is the only important thing.
听第8段材料，回答第12至第14题。
12. When will the man graduate from college
A. Next June. B. Next July. C. This June.
13. What can we know about the man
A. He has some experience in the job.
B. He can speak several languages.
C. He is good at his lessons at college.
14. How much will the company pay the man for the first year
A. $10,500. B. $12,500. C. $15,000.
听第9段材料，回答第15至第17题。
15. When did Tom write to his mother last time
A. Last month. B. Last week. C. Yesterday.
16. Who is Mr. Rogers
A. Tom’s friend. B. Tom’s boss. C. Tom’s teacher.
17. What did Tom tell his mother in his last letter
A. He had made some money.
B. He had lost his part-time job.
C. He had just bought a car.
听第10段材料，回答第18至第20题.
18. Which coaches were derailed (脱轨) from the train D3115 in the incident
A. 1 and 4. B. 4 and 15. C. 15 and 16.
19. Which statement isn’t the cause of this bullet train crash
A. Big problems in emergency and safety management.
B. D3115 caught fire after being struck by lightning.
C. Due to the signal error.
20. Which statement is incorrect about effects of the incident
A. Visitors’ enthusiasm to the bullet train travel routes decreased.
B. The number of people who buy travel insurance is gradually reduce.
C. The incident has caused a national outrage(愤怒).
提升训练2-3
音频2501.2c
第一节（共5小题；每小题1.5分，满分7.5分）
听下面5段对话。每段对话后有一个小题，从题中所给的A、B、C三个选项中选出最佳选项，并标在试卷的相应位置。听完每段对话后，你都有10秒钟的时间来回答有关小题和阅读下一小题。每段对话仅读一遍。
例：How much is the shirt
A. $１9. l5. B. $9. l5. C. $9. 18.
答案是B。
1. Where does the conversation most probably take place
A. In a factory. B. In a hospital. C. In the office.
2. What’s the correct time
A. 6∶ 25 am. B. 6∶35 am. C. 6∶35 pm.
3. When did the man visit the Yellowstone Park
A. This year. B. Last year. C. The year before last.
4．How does the man feel now？
A．Disappointed． B．Regretful. C. Content.
5．Where will the speakers meet？
A．At the museum． B．At the garden． C．At the dentist’s．
第二节（共15小题；每小题1.5分，满分22.5分）
听下面5段对话或独白。每段对话或独白后有几个小题，从题中所给的A、B、C三个选项中选出最佳选项，并标在试卷的相应位置。听每段对话或独白前，你将有时间阅读各个小题，每小题5秒钟；听完后，各小题将给出5秒钟的作答时间。每段对话或独白读两遍。
听下面一段对话，回答第6和第7两个小题。
6. What’s the problem with the man
A. He can’t sleep well.
B. He didn’t pass the exam.
C. He lost touch with friends.
7. What did the woman suggest to him
A. Going to bed earlier.
B. Calling the health service.
C. Taking a course about stress.
听下面一段对话，回答第8至第10三个小题。
8. Where does the conversation take place
A. Over the telephone.
B. In the woman’s home.
C. At an insurance company.
9. Why does the man talk to the woman
A. To make a report.
B. To help rebuild her house.
C. To show sympathy.
10. What will the woman receive
A. A new house. B. Some reports. C. Some money.
听下面一段对话，回答第11和第13三个小题。
11. How long will the holiday last
A. For a week. B. For a month. C. For two weeks.
12. Where does the boy want to go
A. Disneyland and the Fairy Cave.
B. Disneyland and Dinosaur World.
C. Dinosaur World and the Fairy Cave.
13. Why can’t the speakers go to Dinosaur World
A. It’s scary. B. It’s boring. C. It’s far away.
听下面一段对话，回答第14至第16三个小题。
14. Where does the conversation probably take place
A. In a hotel. B. In a store. C. In a restaurant.
15. What do we know about the woman
A. She is warm-hearted. B. She is generous. C. She is active.
l6. What probably is the man
A. The manager. B. A customer. C. A shop assistant.
听下面一段独白，回答第17至第20四个小题。
17. When did drag racing start
A. In 1953. B. In 1943. C. In 1963.
18. Why do drag race tracks have to be straight
A. The cars can’t make a sharp turn.B. Each race doesn’t last long.
C. The course is too short.
19. Why is it sometimes difficult to see the racers
A. The tracks are too straight.B. There is too much smoke.
C. The tyres are huge and fat.
20. What do we know about drag racing
A. It is a sport for teenagers.B. It is similar to other car races.
C. It has become professional.
答案
2501.1
1-5CBACC 6-10ACABA 11-15ABBCC 16-20 BCBAC
2501.1a
1-5 CBACB 6-10 ACBCA 11-15 CAACB 16-20 ABCAB
2501.1b
1-5 BBCAA 6-10 BABBC 11-15 CBCBC 16-20 BACBA
2501.1c
1-5 AABAB 6-10 BACBA 11-15 ABBAA 16-20 ACCAC
2501.2
1-5BACCB 6-10BCACB 11-15AACBB 16-20 CAACA
1-5BACCB 6-10BCACB 11-15AACBB 16-20 CAACA
2501.2a
1-5 ACACC 6-10 ABABC11-15 BBCCC 16-20 BCCBC
2502.2b
1-5 ABCAB 6-10 BACAB 11-15 CACAC 16-20 BCCBC
2502.2c
1-5 BCABA 6-10 ACBAC 11-15 ABABA 15-20 BAABC
