1 máy bay đang bay ngang đều với vận tốc 250m/s, công suất của máy bay là 5.10⁸ W. Tìm lực kéo của động cơ để duy trì tốc độ này.

khi nào 2 nguyên tử liên kết với nhau bằng cách góp chung electron? cho nhận electron?

the road/ we/ get/ office/ Although/ crowded,/ to the / time/ was /to/ on/ managed/.

37. close down /museum /no longer/place/interest

A. They have closed down the museum because it is no longer a place of interest.

B. They closed down the museum, so it is no longer a place of interest.

C. They closed down the museum although it is no longer a place of interest.

D. They are closing down the museum, but it is no longer a place of interest.

38. Take /your shoes / when / go /a Japanese house

A. Take out your shoes when you go into a Japanese house.

B. Take off your shoes when they go into a Japanese house.

C. Take off your shoes when you go into a Japanese house.

D. Take up your shoes when go into a Japanese house.

39. past/children /not have/many / form /entertainment

A. From the past, children not have many forms of entertainment.

B. In the past, children didn’t have many forms of entertainment.

C. In the past, children don’t have many forms of entertainment.

D. For the past, children didn’t have many forms of entertainment.

40. respect/our ancestors/one/traditions/our people

A. To respect our ancestors is one of the traditions on our people.

B. Respect our ancestors is one tradition of our people.

C. Respecting our ancestors was one of the traditions of our people.

D. Respecting our ancestors is one of the traditions of our people.

33. The test was very long. We couldn’t do it in forty-five minutes.

A. We couldn’t do the test in forty-five minutes though it was long.

B. The test was too long for US to do in forty-five minutes.

C. The test was long enough for US to do in forty-five minutes.

D. Forty-five minutes is the time we needed to do the long test.

34. I failed the exam. My mother was disappointed.

A. I failed the exam, but my mother was disappointed.

B. I failed the exam, or my mother was disappointed.

C. I failed the exam, so my mother was disappointed.

D. I failed the exam although my mother was disappointed.

35. We started to play golf last month.

A. We have played golf since last month.                    B. We played golf since last month.

C. We have played golf for last month.                        D. We have started to play golf since last month.

36. “Close your books”, the teacher said to us.

A. The teacher told US close our books.                        B. The teacher told US to closing our books.

C. The teacher told US closing our books.                   D. The teacher told US to close our books.

mọi ngưởi chỉ ra và sửa hộ ạ

Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.

31. Peter is the carefuller driver that I have ever known.

A. the                          B. careftiller                C. that                         D. have ever known

32. Despite the metric system is used throughout the world, it is still not commonly used in the United States.

A. Despite                   B. throughout              C. metric system         D. commonly used

mn cs thể giải chi tiết đc ko ạ

\(A=\left(\dfrac{x-3\sqrt{x}}{x-9}-1\right):\left(\dfrac{9-x}{x+\sqrt{x}-6}-\dfrac{\sqrt{x}-3}{2-\sqrt{x}}-\dfrac{\sqrt{x}-2}{\sqrt{x}+3}\right)\)

unless/ weather/ nice/ we/ stay/ home/ is/ the/ will/ at

số ngiệm của pt \(x^4-3x^2-4=0\) là 
A.2   B.3   C.4     D.1