Chủ đề:
Bài 5: Trường hợp đồng dạng thứ nhấtCâu hỏi:
Cho hình thang ABCD (AB//CD) biết:
AB=4cm; BC=5,4cm; CD=9cm; AD=3,6cm; BD=6cm
a) CM: tam giác ADB đồng dạng với tam giác BCD.
b) Lập tỉ số đồng dạng tính tỉ số đó.
Một con lắc được thả từ vị trí ban đầu A, đi xuống vị trí thấp nhất B, rồi tiếp tục đi lên vị trí C cao nhất. Ở vị trí nào viên bi có động năng lớn nhất?
A. Vị trí B.
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B. Vị trí C.
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C. Vị trí A.
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D. Ngoài ba vị trí trên |
Một vật được thả rơi từ vị trí A, đi qua vị trí B, rồi đi xuống đến vị trí C sát mặt đất. Ở vị trí nào vật có cả động năng và thế năng?
A. Vị trí A.
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B. Vị trí B.
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C. Vị trí C.
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D. Vị trí A và vị trí B. |
Kéo một vật khối lượng 50kg lên độ cao 1,2m bằng mặt phẳng nghiêng dài 2m. Lực kéo vật là:
A. 300N.
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B. 500N.
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C. 600N.
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D. 50N. |
Muốn kéo vật trọng lượng 500N lên cao 1m với lực kéo 200N thì mặt phẳng nghiêng phải dài:
A. 2,5m.
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B. 2m.
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C. 1m.
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D. 5m. |
Để đưa một vật lên cao, cách nào sau đây cho ta lợi hơn về công phải sinh ra?
A. Kéo vật lên bằng mặt phẳng nghiêng.
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B. Kéo vật lên bằng ròng rọc.
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C. Nâng trực tiếp vật theo phương thẳng đứng.
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D. Không có cách nào. |
Đốt cháy hoàn toàn 4,48 lít khí C2H2 trong bình chứa khí oxi. Thể tích khí oxi cần dùng là:
A. 11,2 lít |
B. 4,48 lít
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C. 6,72 lít |
D. 22,4 lít
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Trong những oxit sau: CuO, HgO, BaO, Na2O, PbO. Có bao nhiêu oxit phản ứng với Hidro ở nhiệt độ cao:
A. 5
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B. 3
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C. 2
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D. 4 |
A. haveB. would haveC. had hadD. should have
47. I ______ you sooner had someone told me you were in the hospital.A. would have visitedB. visitedC. had visitedD. visit
48. ______ more help, I would call my neighbor.A. NeededB. Should I needC. I have neededD. I should need
49. ______ then what I know yesterday, I would have saved myself a lot of time and trouble over the years.A. Had I knownB. Did I knowC. If I knowD. If I would know
50. Do you think there would be less conflict in the world if all people ______ the same language?A. spokeB. speakC. had spokenD. will speak
51. If you can give me one good reason for your acting like this, ______this incident again.A. I will never mentionB. I never mentionC. will I never mentionD. I don’t mention
52. If I had known you were asleep, I ______ so much noise when I came in.A. didn’t makeB. wouldn’t have madeC. won’t makeD. don’t make
53. Unless you ______ all of my questions, I can’t do anything to help you.A. answeredB. answerC. would answerD. are answering
54. Had you told me that this was going to happen, I ____________ it.A. would have never believedB. don’t believeC. hadn’t believedD. can’t believe
55. If Jake ______ to go on the trip, would you have gone?A. doesn’t agreeB. didn’t agreeC. hadn’t agreedD. wouldn’t agree
56. Jane: “John went to the hospital alone”,Katy: “If ______, I would have gone with him”.A. had he told meB. he had told meC. he has told meD. he would tell me
57. If you ______, I would have brought my friends over to your house yesterday to watch T.V, but I didn’t want to bother you.A. had studiedB. studiedC. hadn’t studiedD. didn’t study
58. Peter: “Did you need help with your Math last night?”Mary: “If I had needed, I ______ you".A. would callB. calledC. would have calledD. will call
59. If someone ______ into the store, smile and say, “May I help you?”A. comesB. cameC. comeD. should come
60. “Here’s my phone number”.“Thanks. I’ll give you a call if I ______ some help tomorrow”A. will needB. needC. would needD. needed
61. If I didn’t work for an accounting firm, I ______ in a bank now.A. workB. will workC. have workedD. would work
62. The death rate would decrease if hygienic conditions ______ improved.A. wasB. isC. wereD. had been
63. The education in Japan ______ if the basic principles of education had not been taken into consideration.A. would go downB. would have gone downC. went downD. had gone down
64. If there ______, the rice fields could have been more productive.A. had been enough waterB. were enough waterC. would be enough waterD. are enough water
65. The patient will not recover unless he ______ an operation.A. had undergoneB. would undergoC. undergoesD. was undergoing
66. If she ______ him, she would be very happy.A. would meetB. will meetC. metD. should meet
67. If he ______ a thorough knowledge of English, he could have applied for this post.A. had hadB. hadC. hasD. has had
68. If I had enough money, I ______ abroad to improve my English.A. will goB. would goC. wentD. should have go to
69. The bench would collapse if they ______ on it.A. stoodB. standC. standingD. stands
70. If it ______ convenient, let’s go out for a drink tonight.A. beB. isC. wasD. were
VI. Complete the sentences, using the correct form of the words in brackets. 71. People believe that the ____________ water has brought cancer to the local residents. (pollute) 72. Light pollution make us ____________ to see the stars in the sky. (able) 73. Noise is considered as ____________ pollution. (environment) 74. ____________ habitats have been destroyed in recent years. (nature) 75. A number of cleaning products contain ____________ chemicals. (harm) 76. Water samples collected at these villages were seriously ____________with bacteria. (contaminate) 77. An ____________ of agrochemicals is pesticides. (illustrate) 78. Contaminants are usually ____________ to aquatic plants. (poison) VII. Fill in each blank with the correct preposition. 79. Land pollution is responsible for damage done ____________ natural habitat of animals. 80. Americans throw ____________ twenty-eight and a half million tons of plastic in landfills every year. 81. Scientists have come up ____________ new ways of saving energy. 82. Thousands of people were exposed ____________ radiation when the nuclear plant exploded. 83. Waste water from many factories which is dumped ____________ water bodies directly causes water pollution.Our
22. The mechanic checks the car engines every week.The
23. People grow rice in these fields.Rice
24. They send the goods to Vung Tau by coach.The
25. You mustn’t use the machine for over 12 hours a day.The
26. Nam can repair his bike.His
27. Mary helps her grandma every weekend.Mary’s grandma
28. Mai irons her clothes every evening.Mai’s clothes
29. Linda types the reports in this office.The reports
30. The workers will build many new houses in that area next year.Many