Một quả đạn khối lượng m khi bay lên đến điểm cao nhất thì nổ thành hai mảnh. Trong đó một mảnh có khối lượng là  m 3 bay thẳng đứng xuống dưới với vận tốc 20m/s. Tìm độ cao cực đại mà mảnh còn lại lên tới được so với vị trí đạn nổ. Lấy g = 10m/s².

Read and circle the best option A, B, C or D to complete the passage.

One of the first novels in the history of literature (1)……….. written in England in 1719. It was Robinson Crusoe by Daniel Defoe. Daniel Defoe was born (2).............. London in the family of a rich man, When Daniel was a schoolboy, he began to write stories. After (3)............... school, he worked in his father's shop and (4)............. articles for newspapers. Defoe visited many countries and met many people. That helped him (5)............. in his writings.

In 1719, when Defoe was sixty years old, he wrote the novel Robinson Crusoe which (6)............. him famous. Defoe used in his book a true story about a sailor who (7)........... on an island for twenty- eight years. People liked (8)............... novel in England and in many other countries, Daniel Defoe wrote other books. (9)..............., his novel Robinson Crusoe was the (10)............ famous. Defoe was not a rick man when he died in 1731.

Điền vào số 6

A. made

B. did

C. brought

D. let

Một sóng âm có dạng hình cầu được phát ra từ nguồn có công suất P. Tại một điểm cách nguồn một khoảng d có cường độ âm là I. Hệ thức đúng là:

A.   I = 2 P πd 2

B.    I = 2 P πd

C.    I = P 2 πd 2

D.    I = P 4 πd 2

Số nào lớn nhất trong các số được liệt kê trong bốn phương án A,B,C,D dưới đây?

A.  5 . 6 3

B.  6 5 3

C.  5 6 3

D.  5 6 3

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks.

Cartoon film have very (1)_______ limits. If you can draw something, you can (2)_______ it move on the cinema screen. The use of new ideas and advanced computer programs means that cartoons are becoming exciting again for people of all ages. By the end of the 1970s, the cinema world had decided that cartoons were only for children. But soon (3)______ , one or two directors had some original new ideas. They proved that it was possible to make film in which both adults and children could share the fun. However, not every cartoon film was successful. The Black Cauldron, for example, failed, mainly because it was too (4)_______ for children and too childish for adults. Directors learnt from this mistake, and the film companies began to make large (5)______ of money again.

Điền vào số 5

A. totals

B. accounts

C. numbers

D. amounts

Dung dịch chất A có pH = 3. Cần thêm V2 ml nước vào V1 ml dung dịch chất A để pha loãng thành dung dịch có pH = 4. Biểu thức liên hệ giữa V1 và V2 là

A. V2 = 9V1

B. V2 = 10V1

C. V1 = 9V2

D. V2 = V1/10

Tính

(x+2)(9x²-6x+4)