《大学英语（三）》在线作业题库
一、单选题（共 50 道试题，共 100 分。）
1. – Ami, I want this report typed today. – ( ).
A. It'll be ready in the afternoon, sir
B. I'd like you to help me
C. I know nothing about the report
D. Leave it to tomorrow
正确答案：A
2. He( )himself quickly to the new condition of his work.
A. changed
B. altered
C. adjusted
D. varied
正确答案：C
3. We( )the bathroom and plan( )the bedroom this year.
A. painted…to paint
B. is painting… painting
C. paint… to paint
D. have painted…to paint
正确答案：D
4. I don't think this kind of medicine has any( ).
A. answer
B. cause
C. effect
D. work
正确答案：C
5. We consider( )the instrument be adjusted each time it is used.
A. that it necessary
B. it necessary that
C. necessary that
D. necessary of it that
正确答案：B
6. – I wonder if you could help me. – ( ).
A. I could
B. Yes, I do
C. No, not at all
D. Of course
正确答案：D
7. Parliament didn't think the Prime Minister did enough in the improvement of fair employment, ( )he was asked to write to Parliament for further explanation.
A. so
B. therefore
C. since
D. as
正确答案：B
8. – Will you go on a picnic with us tomorrow? – ( ).
A. Yes, but I'll have English classes
B. Sorry. I have an appointment with Dr. Brown
C. I'm afraid I have no idea
D. I won't. It's kind of you
正确答案：B
9. He is over fifty, but he looks as though he( )only in his thirties.
A. were
B. is
C. will be
D. has been
正确答案：A
10. – What about going for a walk? – ( ).
A. Walking is good to you
B. That's all right
C. So, do I
D. Why not? A good idea
正确答案：D
11. Let me( )the case carefully before I draw a conclusion.
A. look up
B. look into
C. look after
D. look out
正确答案：B
12. – The lecture given by professor Smith was really interesting. – ( ).
A. I couldn't agree with you more
B. I'm going to listen to it
C. It sounds reasonable
D. It didn't last too long
正确答案：A
13. – Are you sure about that? – ( ).
A. You needn't worry about that
B. I like the idea
C. Oh, no. I'm afraid of that
D. Oh, yes. I'm absolutely positive
正确答案：D
14. – Excuse me, I didn't mean to bother you. – ( ).
A. There's no problem
B. It's a pleasure
C. That's quite all right
D. I didn't realize that
正确答案：C
15. – Who has done your hair, Susan? – ( ).
A. My hair has been done
B. That hair stylist
C. My hairstyle is cool
D. I have it cut
正确答案：B
16. The population of the earth( )increasing fast. One third of the population here( ) workers.
A. is; are
B. is; has been
C. are; is
D. is; was
正确答案：A
17. John and Mary( )for years before they got married.
A. had been in love
B. had broken up
C. had separated
D. had been divorced
正确答案：A
18. The patient acted on the doctor's( )and finally recovered.
A. advices
B. advice
C. advise
D. advises
正确答案：B
19. – Excuse me, I didn't mean to bother you. – ( ).
A. There's no problem
B. It's a pleasure
C. That's quite all right
D. I didn't realize that
正确答案：C
20. If he was fitter, he( )live longer.
A. 不填
B. will
C. would
D. can
正确答案：C
21. We( )every day when we were children.
A. used to swim
B. used to swimming
C. use to swim
D. use to swimming
正确答案：A
22. In the fifties last century many, new cities( )in the desert.
A. bring up
B. make up
C. grew up
D. build up
正确答案：C
23. – I don't think I'm late. Excuse me, what's the time? – ( ).
A. It says 8:00. But it's 5 minutes slow
B. I'm sorry I've forgot the time
C. I was caught in the traffic jam
D. I'm sorry to keep you waiting
正确答案：A
24. Our Lab was being( )when we visited the university.
A. rebuilt
B. rebuild
C. rebuilding
D. to rebuild
正确答案：A
25. – Oh, you're back at work? How was your holiday? – ( ).
A. We had rain every day and stayed at the hotel most of the time
B. The ten-day holiday was not long enough
C. I was missing you when I was on holiday
D. I heard you were on holiday, too
正确答案：A
26. I started looking after other children( )parents went out to work.
A. who
B. which
C. whose
D. that
正确答案：C
27. – Oh, the box is too heavy. – ( ).
A. What's in it
B. Can I help you to carry it
C. Whose is it
D. May I have a try
正确答案：B
28. The( )is concerned with successful election, whereas the statesman is interested in the future of his people.
A. politics
B. politician
C. political
D. politically
正确答案：B
29. – Do you know if the Andersons are still living there? – ( ).
A. Yes, they do
B. Yes, they are
C. No, there aren't
D. No, they don't
正确答案：B
30. John Preston was tired( )living in east London, in which he had moved after his wife's death.
A. to
B. of
C. at
D. for
正确答案：B
31. That's the( )gentleman I've been telling you about.
A. rather
B. quite
C. very
D. fairly
正确答案：C
32. – Don't take too long at the coffee shop. It's 14:15. – ( ).
A. I'll think your advice over
B. I see. We have 30 minutes left
C. That's no problem
D. I'm afraid so
正确答案：B
33. – Joe will come to the party at Jane and Ian's, won't he? – ( ).
A. Oh, yeah, 1 forgot
B. It's at 8 o'clock
C. Yeah, he's bringing his cousin, Sandy
D. Yeah, it's a nice party
正确答案：C
34. – Could I borrow your CD of English songs? – ( ).
A. No, I am not available
B. I'm sorry. It's not at hand now
C. It's very kind of you
D. Thank you very much
正确答案：B
35. ( )these children know the answer.
A. Most
B. Some
C. Most of
D. Few
正确答案：C
36. – I've got two tickets for the match. Shall we go and watch it together? –( ).
A. The tickets must be expensive
B. The match must be exciting
C. Why not? Let's go
D. The place is too far away
正确答案：C
37. We have our house( )every week by a cleaner.
A. clean
B. cleaned
C. cleaning
D. to clean
正确答案：B
38. He was( )about his new job.
A. over the moon
B. on the moon
C. off the moon
D. above the moon
正确答案：A
39. The bedroom needs( ).
A. decorating
B. to decorate
C. decorate
D. decorated
正确答案：A
40. My aunt has lived in New York( )1995.
A. for
B. during
C. in
D. since
正确答案：D
41. – Hello! Can I get a seat on the 8 pm flight to Detroit? – ( ).
A. Hello! International Airline
B. You'd better look up the schedule first
C. I'm sorry, but it's completely booked
D. I'm afraid you have to change
正确答案：C
42. – I wonder if you could help me. – ( ).
A. I could
B. Yes, I do
C. No, not at all
D. Of course
正确答案：D
43. The teacher spoke so fast that it was hard for the students to( )what he was saying.
A. take in
B. take out
C. take up
D. take over
正确答案：A
44. – How's the movie? Interesting? – ( ).
A. It was shown late until midnight
B. It was starred by a few famous people
C. Far from. I should have stayed home watching TV
D. I was seated far away in the corner
正确答案：C
45. – What's the problem, Harry? – ( ).
A. No problem
B. No trouble at all
C. Thank you for asking me about it
D. I can't remember where I left my glasses
正确答案：D
46. – May I have a look at your photo album? – ( ).
A. Yes, you have
B. It's very interesting
C. This is my girl friend
D. Yes, of course
正确答案：D
47. The beef I ate at the restaurant yesterday is delicious. I'd like to have it again even if it costs( ).
A. as twice much
B. much as twice
C. as much as
D. twice as much
正确答案：D
48. Next year, I( )plan to go to Italy.
A. am
B. 不填
C. had
D. have
正确答案：B
49. – I heard your motorcar was stolen. – ( ).
A. I'm sorry to hear that
B. It doesn't matter
C. Everybody knew it except you
D. Mine wasn't but Bill's was
正确答案：D
50. – Wait here and I'll get my car and go there together. – ( ).
A. I'm sorry to have kept you waiting
B. Your sports car is fabulous
C. I'm afraid I won't wait very long
D. Why bother? It's within walking distance
正确答案：D
一、单选题（共 50 道试题，共 100 分。）
1. Last week I bought a flat( )biggest room faced south.
A. that
B. whose
C. which
D. where
正确答案：B
2. – I think the Internet is very helpful. – ( ).
A. Yes, so do I
B. That's a very good idea
C. Neither do I
D. I'd rather go surfing on it
正确答案：A
3. – Excuse me, when is the next flight from London due to arrive? – ( ).
A. In half an hour
B. An hour before
C. Until the next one
D. Before another one
正确答案：A
4. When we were having a meeting, the director( )the bad news by telephone.
A. was telling
B. was told
C. could tell
D. would tell
正确答案：B
5. John( )to be a teacher before the war, but now he works in a hospital.
A. is used
B. was used
C. used
D. use
正确答案：C
6. – May I help you, madam? – ( ).
A. Sorry, I have no idea
B. Yes, I know what to buy
C. You'd better give me a hand
D. Yes, I'd like 2 kilos of oranges
正确答案：D
7. In China, children( )school at seven.
A. has to start
B. must to start
C. have to start
D. can start
正确答案：C
8. – What's the problem, Harry? – ( ).
A. No problem
B. No trouble at all
C. Thank you for asking me about it
D. I can't remember where I left my glasses
正确答案：D
9. – How do I get to Cairo? – ( ).
A. I'm sorry. I can't understand
B. You could catch the 9:30 flight and change at Paris
C. I'm afraid you have missed the flight
D. I'm glad to show you the way
正确答案：B
10. Once he starts a job, he won't stop( )it is finished.
A. till
B. after
C. before
D. until
正确答案：D
11. Mother was busy. Although she was not watching the basketball on TV, she( )it on the radio.
A. was listening to
B. was hearing
C. was listening
D. was seeing
正确答案：A
12. – Afternoon, sir. Where to? – ( ).
A. Please get me to the airport
B. Please pick me up next time
C. I've been to the airport
D. The plane will take off in an hour
正确答案：A
13. – May I know your address? – ( ).
A. Sure. Here you are
B. I have no idea
C. It's far from here
D. Sorry, I've forgotten
正确答案：A
14. Could you please pay me( )advance?
A. 不填
B. on
C. in
D. for
正确答案：C
15. – Hurry up. The lecture begins at 2:00. – ( ).
A. Don't worry. We've got 20 minutes
B. Thank you. No hurry
C. Never mind. You go if you like
D. The lecture is useful
正确答案：A
16. – How's the movie? Interesting? – ( ).
A. It was shown late until midnight
B. It was starred by a few famous people
C. Far from. I should have stayed home watching TV
D. I was seated far away in the corner
正确答案：C
17. – Oh, you're back at work? How was your holiday? – ( ).
A. We had rain every day and stayed at the hotel most of the time
B. The ten-day holiday was not long enough
C. I was missing you when I was on holiday
D. I heard you were on holiday, too
正确答案：A
18. – I wonder if Henry will come to the party at 8:00 sharp as he's promised. –( ).
A. The party won't start until 8:00
B. Thank you for having the party for me
C. Don't worry. He always keeps his word
D. The party must cost a lot
正确答案：C
19. – Do you know who telephoned me? – ( ).
A. I heard it was Sally
B. Yes, I remember it now
C. No, I didn't phone you
D. Yes, I know you well
正确答案：A
20. Mark is a clerk( )a job in a top bookstore.
A. in
B. with
C. to
D. for
正确答案：B
21. – Would you like to see the menu? – ( ).
A. No, thanks. I already know what to order
B. Your menu is very clear
C. I hear the food here is tasty
D. The setting is very comfortable
正确答案：A
22. – Could I borrow your CD of English songs? – ( ).
A. No, I am not available
B. I'm sorry. It's not at hand now
C. It's very kind of you
D. Thank you very much
正确答案：B
23. They( )for hours.
A. have been driving
B. have been driven
C. drove
D. drive
正确答案：A
24. We have our house( )every week by a cleaner.
A. clean
B. cleaned
C. cleaning
D. to clean
正确答案：B
25. – We want to sit at the table near the window. – I'm sorry, but( )already.
A. it took
B. it takes
C. it is being taken
D. it has been taken
正确答案：D
26. He is the man( )dog bit me.
A. that
B. which
C. who's
D. whose
正确答案：D
27. – Go that way and take a seat. – ( ).
A. No, I'm not tired
B. Thanks, but I'd rather stand
C. Yes, that's a good way
D. It doesn't matter
正确答案：B
28. – I think the Internet is very helpful. – ( ).
A. Yes, so do I
B. That's a very good idea
C. Neither do I
D. I'd rather go surfing on it
正确答案：A
29. – Oh, the box is too heavy. – ( ).
A. What's in it
B. Can I help you to carry it
C. Whose is it
D. May I have a try
正确答案：B
30. – Oh, the box is too heavy. – ( ).
A. What's in it
B. Can I help you to carry it
C. Whose is it
D. May I have a try
正确答案：B
31. She asked me whether( )English.
A. was I
B. am I
C. are you
D. I was
正确答案：D
32. – Could I borrow your CD of English songs? – ( ).
A. No, I am not available
B. I'm sorry. It's not at hand now
C. It's very kind of you
D. Thank you very much
正确答案：B
33. The( )is concerned with successful election, whereas the statesman is interested in the future of his people.
A. politics
B. politician
C. political
D. politically
正确答案：B
34. At present, the most important thing is that Britain needs( )more to improve the relationship with the USA.
A. to do
B. doing
C. to be done
D. do
正确答案：A
35. It is assumed that students at an intermediate level will have a good( )of the basic structures and vocabulary of English.
A. command
B. commanding
C. to command
D. commanded
正确答案：A
36. – Have you got a table for four, Waiter? – ( ).
A. Welcome to our restaurant
B. Yes, sure. This way, please
C. We have booked the seats
D. Here are the menus
正确答案：B
37. In addition to rice, we need to( )our diet with fish, meat and vegetable.
A. supplement
B. replace
C. add
D. eat
正确答案：A
38. You should make( )your house or flat is secure.
A. sure
B. certain
C. understanding
D. knowledge
正确答案：A
39. – Excuse me, would you lend me your calculator? – ( ).
A. Certainly. Here you are
B. Please don't mention it
C. It's nothing
D. Yes, I have a hand
正确答案：A
40. Jean could be a very attractive girl, but she( )to her clothes.
A. pays no attention
B. was paying no attention
C. paid attention
D. had paid attention
正确答案：A
41. No one can possibly recall any detail about the meeting. It is at least five years since it ( ).
A. had taken place
B. was taken place
C. took place
D. was taking place
正确答案：C
42. The teacher spoke so fast that it was hard for the students to( )what he was saying.
A. take in
B. take out
C. take up
D. take over
正确答案：A
43. If I get the new job, I( )buy a better car.
A. 不填
B. will
C. would
D. might
正确答案：B
44. – What subjects are you studying? – ( ).
A. Yes, I'm studying history
B. I'm studying now
C. I'm studying philosophy
D. I'm doing my homework
正确答案：C
45. – The lecture given by professor Smith was really interesting. – ( ).
A. I couldn't agree with you more
B. I'm going to listen to it
C. It sounds reasonable
D. It didn't last too long
正确答案：A
46. – Who has done your hair, Susan? – ( ).
A. My hair has been done
B. That hair stylist
C. My hairstyle is cool
D. I have it cut
正确答案：B
47. China is( )the east of Asia.
A. in
B. to
C. on
D. at
正确答案：A
48. – What do you think about this story? – ( ).
A. Thank you for telling me the story
B. Yes, it's a real story
C. I like it very much
D. So do I
正确答案：C
49. They all( )the job.
A. asked after
B. asked for
C. asked to
D. asked with
正确答案：B
50. – Excuse me, which is the express train to Tokyo? – ( ).
A. The express train is expensive
B. OK. I'll give you a hand
C. Sorry, the express bus has gone
D. On your right. It'll leave in 5 minutes
正确答案：D
一、单选题（共 50 道试题，共 100 分。）
1. – Is there anything serious, doctor? – ( ).
A. I'm going to have another check-up
B. The results of the blood test are wrong
C. No. Just stay in bed and drink more water
D. Yes. You can go home tomorrow
正确答案：C
2. – What's the problem, Harry? – ( ).
A. No problem
B. No trouble at all
C. Thank you for asking me about it
D. I can't remember where I left my glasses
正确答案：D
3. A lecture hall is( )where students attend lectures.
A. there
B. which
C. one
D. that
正确答案：C
4. He is over fifty, but he looks as though he( )only in his thirties.
A. were
B. is
C. will be
D. has been
正确答案：A
5. The policeman was attacked( )a knife.
A. on
B. by
C. for
D. with
正确答案：D
6. – How long have you lived in London? – ( ).
A. I moved here from Paris
B. My whole life
C. I've worked here for almost 10 years
D. I've never traveled there
正确答案：B
7. I thought that this would be a funny trick( )Jim.
A. to play on
B. to have played
C. playing on
D. to being played on
正确答案：A
8. Are you still here? You were here half an hour ago. Who( )for?
A. were you waiting
B. are you waiting
C. did you wait
D. do you wait
正确答案：B
9. The boy( )to school already.
A. has taken
B. has been taking
C. is taken
D. has been taken
正确答案：C
10. Sadam( )for 25 years.
A. got married
B. was married
C. married
D. were married
正确答案：B
11. I prefer the TV( )the radio.
A. to
B. on
C. at
D. with
正确答案：A
12. – Could I borrow your CD of English songs? – ( ).
A. No, I am not available
B. I'm sorry. It's not at hand now
C. It's very kind of you
D. Thank you very much
正确答案：B
13. He is a kind-hearted and( )gentleman.
A. respective
B. respectable
C. respected
D. respectful
正确答案：B
14. I saw she was in a difficulty with all those parcels, so I offered my( ).
A. services
B. money
C. use
D. chance
正确答案：A
15. – I haven't seen Belly for 10 years. – ( ).
A. Either have I
B. Neither have I
C. Haven't I
D. So have I
正确答案：B
16. – Are you feeling better today, Mrs. Silver? – ( ).
A. Don't worry about me
B. Just stay in bed and have a good rest
C. There must be something wrong
D. Yes, thanks doctor. But I still feel dizzy
正确答案：D
17. – Ami, I want this report typed today. – ( ).
A. It'll be ready in the afternoon, sir
B. I'd like you to help me
C. I know nothing about the report
D. Leave it to tomorrow
正确答案：A
18. Once he starts a job, he won't stop( )it is finished.
A. till
B. after
C. before
D. until
正确答案：D
19. – Let's take a walk. – ( ).
A. Yes, let's
B. Oh, thanks
C. Yes, please
D. No, thank you
正确答案：A
20. She( )talking when I am watching TV.
A. always
B. keeps
C. forever
D. still
正确答案：B
21. – Do you know who telephoned me? – ( ).
A. I heard it was Sally
B. Yes, I remember it now
C. No, I didn't phone you
D. Yes, I know you well
正确答案：A
22. – Jack, are you leaving now? It's 7:20. – ( ).
A. Yes, it's still early
B. No, thirty minutes is enough
C. Yes, the bag is not ready
D. No, I'll set off in 30 minutes
正确答案：D
23. You( )to lock the door at night.
A. should
B. ought
C. must
D. shall
正确答案：B
24. – May I know your address? – ( ).
A. Sure. Here you are
B. I have no idea
C. It's far from here
D. Sorry, I've forgotten
正确答案：A
25. My teacher told me( )to English people as much as I can to practise my English.
A. talking
B. talk
C. talked
D. to talk
正确答案：D
26. The blue whale is( )largest animal in the world.
A. a
B. the
C. 不填
D. the most
正确答案：B
27. She was convicted( )murder.
A. to
B. in
C. with
D. of
正确答案：D
28. The next train to Beijing( )here at 3'o clock.
A. is due
B. is due to
C. is due for
D. due to
正确答案：A
29. – Excuse me, how can I get to the nearest supermarket? – ( ).
A. It's not very far from here
B. The supermarket is very large
C. The goods there are very expensive
D. Sorry, sir. I'm a stranger here myself
正确答案：D
30. – We want to sit at the table near the window. – I'm sorry, but( )already.
A. it took
B. it takes
C. it is being taken
D. it has been taken
正确答案：D
31. – I haven't seen Belly for 10 years. – ( ).
A. Either have I
B. Neither have I
C. Haven't I
D. So have I
正确答案：B
32. – Go that way and take a seat. – ( ).
A. No, I'm not tired
B. Thanks, but I'd rather stand
C. Yes, that's a good way
D. It doesn't matter
正确答案：B
33. I'd like to know what you( )the plants I gave you.
A. made for
B. dealt with
C. live on
D. did with
正确答案：D
34. – Could I borrow your CD of English songs? – ( ).
A. No, I am not available
B. I'm sorry. It's not at hand now
C. It's very kind of you
D. Thank you very much
正确答案：B
35. John( )to be a teacher before the war, but now he works in a hospital.
A. is used
B. was used
C. used
D. use
正确答案：C
36. I( )her to marry me and she agreed.
A. ask
B. asked
C. told
D. tell
正确答案：B
37. – Oh, the box is too heavy. – ( ).
A. What's in it
B. Can I help you to carry it
C. Whose is it
D. May I have a try
正确答案：B
38. – Must we hand in our homework now? – ( ).
A. Yes, you will
B. Yes, you mustn't
C. No, you needn't
D. No, you mustn't
正确答案：C
39. ( ), we keep records on all the experiments so that we may have enough data.
A. As a whole
B. As a rule
C. On the average
D. By all means
正确答案：B
40. – I don't think I'm late. Excuse me, what's the time? – ( ).
A. It says 8:00. But it's 5 minutes slow
B. I'm sorry I've forgot the time
C. I was caught in the traffic jam
D. I'm sorry to keep you waiting
正确答案：A
41. When a fire( )at the National Exhibition, at least ten priceless paintings were completely destroyed.
A. broke off
B. broke out
C. broke down
D. broke up
正确答案：B
42. Did you have a neighbor who was always( )your business?
A. doing
B. making it
C. getting above
D. poking his nose into
正确答案：D
43. ( )for the Olympic Games begins about ten years in advance.
一、句子改错（共5道小题，共25.0分） 1. This is such a beautiful day that everyone around us feel like going out for a walk. A B C D A. A B. B C. C D. D 2. Neither John and his father was able to wake up early enough to catch the morning train. A B C D A. A B. B C. C D. D
3. He finds it easier to do the cooking himself than teaching his wife to cook. A B C D A. A B. B C. C D. D 4. Despite his old age, he is still very healthful and often works in the field. A B C D A. A B. B C. C D. D
5. The information which she was injured in the accident was given by Liz. A B C D A. A B. B C. C D. D 二、阅读理解（共1道小题，共50.0分）
1. Today, as in every other day of the year, more than 3,000 U.S. adolescents will smoke their first cigarette on their way to becoming regular smokers as adults. During their lifetime, it can be expected that of these 3,000 about 23 will be murdered, 30 will die in traffic accidents, and nearly 750 will be killed by a smoking-related disease. The number of deaths attributed to cigarette smoking outweighs all other factors, whether voluntary or involuntary, as a cause of death. Since the late 1970s, when daily smoking among high school seniors reached 30 percent, smoking rates among youth have declined. While the decline is impressive, several important issues must be raised. First, in the past several years, smoking rates among youth have declined very little. Second, in the late 1970s, smoking among male high school seniors exceeded that among female by nearly 10 percent. The statistic is reversing. Third, several recent studies have indicate high school dropouts have excessively high smoking rates, as much as 75 percent . Finally, though significant declines in adolescent smoking have occurred in the past decade, no definite reasons for the decline exist. Within this context, the National Cancer Institute (NCI) began its current effort to determine the most effective measures to reduce smoking levels among youth. 1. According to the author, the deaths among youth are mainly caused by _____. A. traffic accidents B. smoking-related diseases C. murder D. all of these 2. Every day there are over _____young people who will become regular smoker. A. 75 B. 23 C. 30 D. 3,000 3. By "dropout" (in paragraph 3) the author means______. A. students who failed the examination
1.质点运动学单元练习（一）答案 1．B 2．D 3．D 4．B 5．3.0m ；5.0m （提示：首先分析质点的运动规律，在t <2.0s 时质点沿x 轴正方向运动；在t =2.0s 时质点的速率为零；，在t >2.0s 时质点沿x 轴反方向运动；由位移和路程的定义可以求得答案。） 6．135m （提示：质点作变加速运动，可由加速度对时间t 的两次积分求得质点运动方程。） 7．解：（1）)()2(22 SI j t i t r )(21m j i r )(242m j i r )(3212m j i r r r )/(32s m j i t r v （2）)(22SI j t i dt r d v )(2SI j dt v d a )/(422s m j i v )/(222 s m j a 8．解： t A tdt A adt v t o t o sin cos 2 t A tdt A A vdt A x t o t o cos sin
9．解：（1）设太阳光线对地转动的角速度为ω s rad /1027.73600 *62 /5 s m t h dt ds v /1094.1cos 32 （2）当旗杆与投影等长时，4/ t h s t 0.31008.144 10．解： ky y v v t y y v t dv a d d d d d d d -k y v d v / d y C v ky v v y ky 2 22 121, d d 已知y =y o ，v =v o 则2 020 2 121ky v C )(22 22y y k v v o o
题目1 正确 获得1.00分中的1.00分 The children _______ play with them. 选择一项： a. are wanting that b. want me for c. want me to d. want that I 反馈 正确答案是：want me to 题目2 正确 获得1.00分中的1.00分 Don't laugh ________ people when they are _____trouble. 选择一项： a. in….at… b. at….at… c. on… in… d. at… in… 反馈 正确答案是：at… in… 题目3 正确 获得1.00分中的1.00分 - Why does he look sad? - There are so many problems ____________. 选择一项： a. remaining to settle b. remained settling c. remaining to be settled d. remained to be settled 反馈
正确答案是：remaining to be settled 题目4 正确 获得1.00分中的1.00分 Charles regretted _____the TV set last year. The price has now gone down. 选择一项： a. of b. to buy c. from d. buying 反馈 正确答案是：buying 题目5 不正确 获得1.00分中的0.00分 The old lady is quarrelling as if she ______ mad. 选择一项： a. is b. were c. was d. are 反馈 正确答案是：were 题目6 正确 获得1.00分中的1.00分 Uncle Sam sent him a _______ bicycle as a birthday present. 选择一项： a. red sports new b. new red sports c. sports new red d. new sports red
大学英语(3)课程作业_A 一单选题 1. When I said that some people are stupid I was not ___ you. reference refer referring referring to 本题分值： 4.0 用户得分： 0.0 用户解答： reference 标准答案：referring to 2. ___ your step，or you might fall into the water. See Watch Miss Look at 本题分值： 4.0 用户得分： 0.0 用户解答： See 标准答案：Watch 3. Professor Lee visits China almost ___. twice a year a twice year a year twice a year two times 本题分值： 4.0 用户得分： 4.0 用户解答： twice a year 标准答案： twice a year 4. The missing boys were last seen ___ near the river. playing to be playing play to play 本题分值： 4.0 用户得分： 4.0 用户解答： playing
5. China is ___ old country with ___ long history. the, a a, an an, a an, the 本题分值： 4.0 用户得分： 0.0 用户解答： the, a 标准答案：an, a 6. I learn ___ my cost that a broken leg can be very painful. at on to in 本题分值： 4.0 用户得分： 0.0 用户解答： at 标准答案：to 7. It was ___ that he had to ask for help. a so big work a so big job such a big work a such big job 本题分值： 4.0 用户得分： 0.0 用户解答： a so big work 标准答案：such a big work 8. There was ___ in the meeting room. no one another anyone the one 本题分值： 4.0 用户得分： 0.0 用户解答： no one
数字图像课后习题答案 第一章 1、说明图象数字化与图象空间分辨率之间的关系 答。数字图像的分辨率是数字图像数字化精度的衡量指标之一。图像的空间分辨率是在图像采样过程中选择和产生的，图像的空间分辨率用来衡量数字图像对模拟图像空间坐标数字化的精度。一般来说，采样间隔越大，所得图像像素数越少，空间分辨率低，质量差，严重时出现像素呈块状的国际棋盘效应。采样间隔越小，所得图像像素数越多，空间分辨率高，图像质量好，但数据大。 2、说明图象数字化与图象灰度分辨率之间的关系。 答。图像的灰度分辨率是图像量化过程中选择和产生的，灰度分辨率是指对应同一模拟图像的高度分布进行量化操作所采用的不同量化级数。量化等级越多，所得图像层次越丰富，灰度分辨率越高，图像质量好，但数据量大。量化等级越少，图像层次越丰富，灰度分辨率低，会出现假轮廓现象，图像质量变差，但数据量小。 3、看图说明伪彩色图象采集卡的工作原理，并说明LUT的原理和作用。 答。伪彩色图像采集卡的工作原理是，视频信号输入经过视频信号的A/D变换后，经帧存储器后进行计算机处理，输出显示，然后径伪彩色查询表LUT，实现为彩色输出功能，最后按D/A以控制彩色监视器的电子枪强度，形成彩色。LUT的作用是具有为彩色查询表功能的LUT的作用是输出为彩色。 第二章 1、如何快速计算DCT，对奇异点如何处理？ 答。DCT的快速算法将N点的序列延拓成2N点序列，用FFT求2N点序列的离散傅里叶变换，由此得N点的DCT.对于奇异点的单独定义。用奇异值分解的DCT的数字图像水印法来处理。 第三章 1、试述直方图均衡化的增强原理。 答。对原始图像中的像素灰度作某种映射变换，使变换后的图像灰度的概率密度是均匀分布的，即变换后的图像是一副灰度级均匀分布的图像。设归一化的灰度变量r,s；T(r)为单调递增函数，保证灰度级从黑到白的次序不变；有0≤T(r)≤1，确保映射后的像素灰度在允许的范围内S的概率密度函数为分布函数的f(s)=p(R)d(r)导数,左右两边求导,结果图像的直方图为均匀的,P(s)=1,两边积分,变换函数为r的累积直方图函数时，能达到直方图均衡化的目的,对于数字图像，用频率代替概率. 2试述规定化直方图增强原理； 答。r, z分别表示原始图像的灰度和希望得到的结果图像的灰度（归一化）；对原始图像作直方图均衡化处理；对结果图像作直方图均衡化处理；都为均匀的直方图。按照希望得到的图像的灰度概率密度函数pz(z)，作均衡，求得变换函数G(z)；用得到的灰度级s作逆变换z= G-1(s)。 3探讨图象平滑与图象锐化的异同点及它们的适用领域 答，相同点是都属于图像增强，为了改善图像的效果，都有模板，空域和频域的处理方法。不同点是图像平滑是为了消除噪声，有利于抽取对象特征进行分析，而图像锐化属于微分运算。图像平滑处理后较模糊，锐化则突出细节边缘。平滑模板是系数只有正的所有系数相加后为1，而图像锐化模板的系数有正也有负，所有系数相加后为零。图像使用于图像传输，而锐化用于医疗图片的边缘检测和图像分割技术。 4探讨空域增强处理与频域增强处理的特点，比较其性能。 答，空域增强处理是对图像的像素直接处理，利用变换函数T(r)直接进行变换，获得处理后的图像。频域增强处理的修改图像的傅氏变换为基础的，在滤波器处理后变换获得处理后图像。频域性能较好。
第一章 质点运动学（1） 一、填空题 1. 位矢 速度 2. m 3- m 5 12-?s m 22-?s m 3. 127-?-s m 113-?-s m 4. j t i t v ???23)14(-+= j t i a ???64-= j i v ???129-= j i a ? ??124-= 二、选择题 1. B 2. A 3. 某物体的运动规律为2d /d v t Av t =-，式中的A 为大于零的常数，当0=t 时,初速 为 0υ,则速度υ与时间t 的函数关系是（C ） 4. B 三、计算题 1. 质点的运动方程为2205t t x +-=和2 1015t t y -= ，式中y x ,单位为m ，t 的单位为s ，试求：（1）初速度的大小和方向；（2）初始加速度的大小和方向 答案：=v ?j t i t ??)2015()540(-+-，=a ?j i ??2040-， t=0时=v ?j i ??155+-，=a ?j i ??2040- （1）初始速度大小：181.15-?≈s m v ， 与x 轴夹角为ο4.108=α （2） 初始加速度大小：272.44-?≈s m a ， 与x 轴夹角为ο6.26-=β 2. 质点沿直线运动，加速度24t a -=，如果=2s t 时，=5m x ，-1=2m s v ?，试求质点 的运动方程。 答案：5310212124+-+- =t t t x 3. 质点的加速度22x a -=，x =3m 时，v =5m/s ，求质点的速度v 与位置x 的关系式。 答案：613 432+-=x v
第一章 质点动力学 (2) 一、填空题 1. 角坐标 角速度 角加速度 2. （1）=ωdt d θ =α22dt d θ （2）积分 角速度 运动方程)(t θ 3. 圆周 匀速率圆周 4. θsin v 二、选择题 1. C 2. D 3. B 三、计算题 1. 一质点在半径为m 10.0的圆周上运动，其角位置为2 42t +=θ，式中θ的单位为 rad ，t 的单位为s 。 （1）求在s t 0.2=时质点的法向加速度和切向加速度。（2）t 为多少时，法向加速度和切向加速度的值相等？ 答案：（1）26.25-?=s rad a n ，28.0-?=s rad a t （2） s t 35.0= 2. 质点在oxy 平面内运动，其运动方程为j t i t r ???)3()2(2-+=，式中各物理量单位为国际制单位。求：（1）质点的轨迹方程；（2）在1t =1s 到2t =2s 时间内的平均速度； （3）1t =1s 时的速度及切向和法向加速度；（4）1t =1s 时质点所在处轨道的曲率半径。 答案：（1）432 x y -=， （2）j i v ???32-= （3）t=1s 时，j i v ???221-=，j a ??2-=，2=τa ，2=n a ， （4）24=ρ
大学英语三离线作业答 案 Document serial number【NL89WT-NY98YT-NC8CB-NNUUT-NUT108】
离线作业试卷列表2 一、单选? 1.第一部分：交际用语（共5小题；每小题3分，满分15分）- Would you be interested in seeing a film tonight- ____C______?分值：3 A. Not at all.??? B. Are you sure??? C. Great! I'd love to ??? D. You're welcome.???? 2.第一部分：交际用语（共5小题；每小题3分，满分15分）- Excuse me, could you tell me the way to P eople's Square- ____B______?分值：3 A. I don't understand you.??? B. Sorry, I'm a stranger here.??? C. Why don't you take a taxi??? D. Don't bother me.???? 3.第四部分：完形填空（共10小题；每小题1分，满分10分）30?C 分值：1 A. on mind??? B. in heart??? C. in mind??? D. on your mind???? 4.第四部分：完形填空（共10小题；每小题1分，满分10分）29 B?分值：1 A. with??? B. for??? C. to??? D. in???? 5.第四部分：完形填空（共10小题；每小题1分，满分10分）28 B?分值：1 A. impossible??? B. wonderful??? C. incapable??? D. practical???? 6.第一部分：交际用语（共5小题；每小题3分，满分15分）- I've got the first prize in the dancing ____C______?分值：3 A. You're welcome.??? B. It's very kind of you.??? C. Please accept my congratulations.??? D. Oh, really, I can't believe my ears.???? 7.第一部分：交际用语（共5小题；每小题3分，满分15分）- I've passed the ___D_______?分值：3 A. What a pity!??? B. I have the examination.??? C. Come on.??? D. Congratulations.???? 8.第一部分：交际用语（共5小题；每小题3分，满分15分）- I'm suffering from a ________A__?分值：3
《大学英语（三）》在线作业题库 一、单选题（共 50 道试题，共 100 分。） 1. – Ami, I want this report typed today. – ( ). A. It'll be ready in the afternoon, sir B. I'd like you to help me C. I know nothing about the report D. Leave it to tomorrow 正确答案：A 2. He( )himself quickly to the new condition of his work. A. changed B. altered C. adjusted D. varied 正确答案：C 3. We( )the bathroom and plan( )the bedroom this year. A. painted…to paint B. is painting… painting C. paint… to paint D. have painted…to paint 正确答案：D 4. I don't think this kind of medicine has any( ). A. answer B. cause C. effect D. work 正确答案：C 5. We consider( )the instrument be adjusted each time it is used. A. that it necessary B. it necessary that C. necessary that D. necessary of it that 正确答案：B 6. – I wonder if you could help me. – ( ). A. I could B. Yes, I do C. No, not at all D. Of course 正确答案：D 7. Parliament didn't think the Prime Minister did enough in the improvement of fair employment, ( )he was asked to write to Parliament for further explanation. A. so B. therefore
【5-9】钢筋混凝土偏心受压柱，截面尺寸为b=500mm，h=650mm，=。截面承受轴向压力设计值 N=2310KN，柱顶截面弯矩设计值,柱底截面 弯矩设计值。柱挠曲变形为单曲率。弯矩作 用平面内柱上下两端的支撑长度为4.8m，弯矩作用平面外柱的计算长度=6.0m。混凝土强度等级为C35，纵筋采用 HRB500级钢筋。采用对称配筋，求受拉钢筋和受压钢筋 。 【解】查附表3，=435N/,=410N/;查附表 10，,弯矩作用平面内柱计算长度 。 （1）判断构件是否考虑附加弯矩 杆端弯矩比==0.964>0.9 （2）计算构件弯矩设计值 =h-=650mm-50mm=600mm
==22mm>20mm,取 ( =1+( M= (3)判别偏压类型 =+ =263+22=285mm e= 且2=250=100mm,判定为大偏心受压。 （4）计算钢筋面积 将代入式（5-51），得
= =1003 选4D18（==1018）,截面总配筋率为 ρ==,满足要求。（5）验算垂直于弯矩作用平面的受压承载力。 查表5-1，?=0.95。有式（5-1）得 ?() = =5354.23 =5354.23KN>N=2310KN 满足要求。 【5-10】钢筋混凝土偏心受压住，截面尺寸b=500mm,h=500mm,=。截面承受轴向压力 设计值N=200KN，柱顶截面弯矩设计值,柱
底截面弯矩设计值。柱挠曲变形为单曲率。 弯矩作用平面内柱上下两端的支撑长度为4.2m，弯矩作用平面外柱的计算长度=5.25m。混凝土强度等级为C35， 纵筋采用HRB500级钢筋。采用对称配筋，求受拉和受压钢筋。 【解】查附表3，=435N/,=410N/;查附表 10，,弯矩作用平面内柱计算长度 。 （1）判断构件是否考虑附加弯矩 杆端弯矩比==0.93>0.9 （2）计算构件弯矩设计值 =h-=500mm-50mm=450mm ==16.7mm<20mm,取
大物作业答案
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本习题版权归物理与科学技术学院物理系所有，不得用于商业目的 《大学物理》作业 No.5 光的衍射 班级 ________ 学号 ________ 姓名 _________ 成绩 _______ 一、选择题： 1. 在如图所示的单缝夫琅禾费衍射装置中，设中央明纹的衍射角范围很小。若使单缝宽度a 变为原来的 23，同时使入射的单色光的波长λ 变为原来的3 / 4，则屏幕E 上单缝衍射条纹中央明纹的 宽度?x 将变为原来的 [ ] (A) 3 / 4倍 (B) 2 / 3倍 (C) 9 / 8倍 (D) 1 / 2倍 (E) 2倍 解：单缝衍射中央明纹两侧第一暗纹中心间距离为中央明纹线宽度： θtg 2f x =? 由第一暗纹中心条件： λθ=sin a 即 a λ θ= sin 当θ 小时，有 θθsin tg ≈ ∴ a f x λ 2≈? 已知题意：122 3 a a = ， 4/312λλ= ,可得 ()()1112 2 2 2 12212x a f a f x ?=???? ??= =?λλ ∴ a 、λ 改变后的中央明纹宽度(?x )2变为原来宽度(?x )1的1/2 故选D 2. 波长 λ=500nm(1nm=10- 9m)的单色光垂直照射到宽度a =0.25 mm 的单缝上，单缝后面 放置一凸透镜，在凸透镜的焦平面上放置一屏幕，用以观测衍射条纹。今测得屏幕上中央明条纹一侧第三个暗条纹和另一侧第三个暗条纹之间的距离为d =12 mm ，则凸透镜的焦距f 为 [ ] (A) 2 m (B) 1 m (C) 0.5 m (D) 0.2 m (E) 0.1 m 解：由单缝衍射第一暗纹中心条件： λθ±=sin a 可得中央明纹线宽度a f x λ 2=? 而其余明纹线宽度a f x λ ='? 故中央明条纹一侧第三个暗条纹和另一侧第三个暗条纹之间的距离应是其余明纹线宽度 单缝 λa L E f O x y
大学英语三作业 第一部分：交际用语（共5小题；每小题3分，满分15分） 1. — It’s really a good dinner, isn’t it? — __B_____________________ A. Yes, I’d like to go. B. Yes, the food is just wonderful. C. I’m glad to hear that. D. It’s very nice of you to say so. 2. — I’d like to open an account here. — ____C___________________ A. Yes, Madam. How can I help you? B. Oh, yes, please. C. I see. What kind of account, please? D. You can do whatever you like. 3. — Thank you for this wonderful party. — _______C________________ A. It’s my pleasure. B. No, it’s not so good as you say. C. I’m so glad you enjoy it. D. What do you think about it now? 4. — I was wondering if you’d like to go skating? — _________C______________ A. Are you really interested in going? B. I often go skating on Saturday. C. I’d love to, but I’m afraid I can’t do it today. D. Don’t you like it? 5. — Have a nice weekend! — ________D_______________ A. Of course I will. B. So will I. C. Not at all. D. Thanks. You too! 第二部分：阅读理解（共10小题；每小题3分，满分30分） Passage 1 To us it seems so natural to put up an umbrella to keep the water off when it rains. But actually the umbrella was not invented as protection against rain. Its first use was as a shade (遮光物)against the sun! Nobody knows who first invented it, but the umbrella was used in very ancient times. Probably the first to use it were the Chinese, way back in the 11 century BC. We know that the umbrella was used in ancient Egypt and Babylon as a sunshade. And there was a strange thing connected with its use: it became a symbol of honour and authority. In the Far East in ancient times, the umbrella was allowed to be used only by royalty or by those in high
阶段作业一 一、单项选择题（共10道小题，共100.0分） 1. All the signs _________ an early resumption of the battle. 2. 1.point at 2.point 3.point out 4.point to 3. In a time of social reform, people's state of mind tends to keep ________ with the rapid changes of society. 4. 1.step 2.progress 3.pace 4.touch 5. After he had been asked the same question many times, his answer became _________ . 6. 1.machine
2.mechanics 3.mechanic 4.mechanical 7. He seems to be _________ enough to climb to the mountain top in an hour. 8. 1.radiant 2.conscientious 3.conspicuous 4.energetic 9. The University ________him an honorary degree. 10. 1.drained 2.awarded 3.approached 4.glimpsed 11.
Copper ________ electricity. 12. 1.cracks 2.equips 3.strikes 4.conducts 13. I'm firm in my________ that he is a good teacher. 14. 1.behaviour 2.believe 3.beloved 4.belief 15. The sting ________ him in his dislike of bee. 16. 1.confirmed 2.firmed 3.formed 4.confused
第一章 1.给出N 、R 、φ、ψ和r 的微分谱分布和积分普分布的定义，并写出用βE 表示这些辐射量的表达式。 解：N 、R 、φ、ψ和r 均存在着按粒子能量分布，如果用Q 代表这些辐射量，用 E 代表 粒子能量(不包括静止能)，则Q(E)是Q 的积分分布，它是能量为0—E 的粒子对Q 的贡献，QE 是Q 的微分分布，它是能量在E 附近单位能量间隔内粒子对Q 的贡献，用P E 表示以上辐射量。 dE d P E E Ω=??Ω ? ψ=dE d EP E E Ω??Ω R=ααdEd dtd EP E t E Ω????Ω r=dE EP E E ? N=ααdEd dtd p E t E Ω??? ?Ω 2.判断下表所列各辐射量与时间t 、空间位置γ、辐射粒子能量E 和粒子运动方向Ω之间是否存在着函数关系，存在函数关系者在表中相应位置处划“”，不存在则划“”号。 解：如下表所示 3.一个60C 0点源的活度为×107Bq ，能量为和的γ射线产额均为100%。求在离点源1m 和10m 处γ光子的注量率和能量注量率，以及在这些位置持续10min 照射的γ光子注量和能量注量。 解：先求在离点源1m 处γ光子注量和能量注量率 1 262 721.10892.51 14.34%100107.34%100--?=????=?=s m r A π? 2 13 1372 211114.34%)10010602.133.1%10010602.117.1(107.34% 100)(?????+?????= ?+= r E E A πψ 220.10108.1m w ?= 在离点源10m 处γ光子注量和能量注量率 1242 722.10892.510 4%100103074%100--?=???=?=s m r A ππ?
北京师范大学网络教育大学英语三作业三 What would you like to drink? - _______ . orange juice, please - I'm engaged. - _______ on your engagement. Congratulations - I'd like to make a reservation for two days. My name is Li Ming. - _______Single or double room? - Hello, may I speak to John? -__________Just a second, please. - Thank you for your invitation. - ________.It's a pleasure 第二部分：阅读理解（共10小题；每小题3分，满分30分） It is _______ since a man being operated felt all the pain. few years Long ago, when the sick man was operated on, he _______ . could feel all the pain Using the laughing gas, the people did not seem to _______ . feel pain If a man took less laughing gas than he should have when an operation went on, he _______ . still felt pain One who took too much of the laughing gas _______ . would die Miss Jordan decided to become a lawyer________.when she was in high school What did she study at Boston University? ______.Law The word "restless" in Paragraph5 means in its sentence_______.not satisfied with me life she was living and wanting to have some new experience In her political life she won ________ in 1972. a seat in the U.S. Congress Miss Jordan was the first black woman_________.from the South to be elected to Congress 第三部分：词汇与结构（共5小题；每小题3分，满分15分） Hundreds of people ____their homes in the floods. Lost I don't believe Bush is elected as the President. There ____ some mistake with the vote. must be Had you come here one minute earlier, you ____ the school bus. But now you had to wait for another ten minutes for the next school bus. would have caught Her case has attracted an enormous ____ of public sympathy. Amount Not matter ____, the heavy box is still immoveable. how hard I am pushing 第四部分：完形填空（共10小题；每小题1分，满分10分） American people divide their days 21 several blocks 22 time, and plan different activities 23 different times. American time is "on the dot". If something is supposed to happen 24 eight o'clock, it will begin at eight. American value promptness and may become angry if a person is more than 15 minutes late 25 a good reason. If you know you are going to be late, call 26 advance and let someone know. 27 you arrive late, you should apologized and explain why. Americans arrive 28 time for doctors" appointments. The doctor may keep you 29 , but if you keep the doctor waiting, you may get a bill 30 the doctor's time! 21into 22of 23for 24at 25without 26for 27If 28on 29waiting 30for 第五部分：英译汉（共3小题；每题5分，满分15分） I'm very much eager to improve my oral English. 我非常渴望提高我的英语口语 He has sympathy for all the poor people. 他同情所有的穷人 He offered to help us with our work. 他主动帮助我们的工作 第六部分：写作（满分15分） 请根据下面所给的题目用英语写出一篇不少于80词的短文。 How to keep Healthy
精品文档阅读理解题分第1题 (20) Many a young person tells me he wants to be a writer. I always encourage and such people, but I also explain that there's a big difference between a writerwriting. In most cases these individuals are dreaming of wealth and fame, not the long hours at a typewriter. “You have got to want to write,”I said to them, “not want to be a writer.” The reality is that writing is a lonely, private and poor-paying affair. For every writer kissed by fortune there are thousands more whose longing is never rewarded. When I left a 20-year career in the U.S. Coast Guard to become a freelance writer, I had no prospects at all. What I did have was a friend who found for me my room in a New York apartment building. It didn't even matter that it was cold and had no bathroom. I immediately bought a used typewriter and felt like a genuine writer. and began to doubt After a year or so, however, I still hadn't got a breakmyself. It was so hard to sell a story that barely made enough to eat. But I knew I to write. I had dreamed about it for many years. I wasn't going to be one wanted of those people who died wondering. What if? I would keep putting my dream to test (even though it meant living with uncertainty and fear of failure). This is the shadow-land of hope, and anyone with a dream must learn to live there. ．阅读理解1 (4.0) 分 The passage is meant to _______ . warn young people of the hardship that a successful writer has to experience 、A advise young people to give up their idea of becoming a professional writer B、 show young people it is unrealistic for a writer to pursue wealth C、 D、encourage young people to pursue a writing career 2．阅读理解 (4.0) 分 What can be concluded from the passage? 精品文档． 精品文档 rewarding. ａｎｄ、Genuine writers often find their work interesting A