một hộp chứa cát có khối lượng 100kg ban đầu đang đứng yên được kéo trên sàn nhà bằng lực kéo 1200N. hệ số ma sát giữa hộp với sân là 0,38. lấy g=9,8m/s2 . góc giữa dấy kéo và phương ngang là bao nhiêu để kéo được lượng cát lớn nhất tính khối lượng cát và hộp khi đó

Mark the letter A, B, C or D on your answer sheet to indicate the word whose underlined part is pronounced differently from that of the rest in each of the following sentences.
Question 1. A. groups                  B. desks                         C. units                     D. lessons Question 2. A. stay           B. fashion                      C. game                    D. lazy

Mark the letter A, B, C or D on your answer sheet to indicate the word that differs from the other three in the position of stress in each of the following sentences.
Question 3. A. forget                    B. discuss                      C. answer                  D. explain

Question 4. A. airport                   B. vision                        C. ticket                    D. mistake

Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions.
Question 5. Our friends were very                     about die football match last night.

A. excited                        B. surprised                      C. amazed                        D. amused

Question 6. The man                     lives next door to us is a tour guide.

A. whose                         B. which                          C. whom                          D. who

Question 7. He asked the children                     at bedtime, but they kept making noise.

A. didn‟t talk                      B. not talked                    C. not to talk                    D. not talking

Question 8. The water clock was made by the Chinese                  _ the 11th century.

A. at                                 B. to                                 C. on                                D. in

Question 9. You have to fill in an                     form for admission to the university at the front desk.

A. apply                           B. applicator                     C. application                   D. applicable

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