Everyone wants to reduce pollution. But pollution problem is as complicated as it is serious. It is complicated because much pollution is caused by things that benefit people. For example, exhaust from automobiles causes a large percentage of all air pollution. But automobiles provide transportation for millions of people. Factories discharge much of the material which pollutes the air and water, but factories give employment to a large number of people. Too much fertilizer or pesticide can ruin soil, but fertilizers and pesticide are important aids to the growing of crops. Thus, to end or reduce pollution immediately, people would have to stop using many things that benefit them. Most people do not want to do that, of course. But pollution can be gradually reduced in several ways.

Answer the questions:

Why is the pollution problem complicated?

Give the correct form of the verbs in brackets.

He suggests (take) the bus to school.

Cho hình lăng trụ tam giác A B C . A ' B ' C ' có đáy là tam giác ABC vuông tại A, A B = 3 , A C = 4  và A A ' = 61 2 .  Hình chiếu của B’ lên mặt phẳng A B C  là trung điểm cạnh BC, điểm M là trung điểm cạnh A ' B ' . Tính cosin của góc tạo bởi hai mặt phẳng A M C '  và (A’BC) bằng:

A.  11 3157 .

B.  13 65 .

C.  33 3517 .

D.  33 3157 .

Choose the best answer A, B, C or D to complete the following sentences.

What’s ____________ film you’ve ever seen?

A. good

B. the best

C. better

D. well

Although he took a taxi, Bill still arrived late for the concert.

→ Despite ........................................................................................................................

Điền số thích hợp vào ô trống:

Biết x x 6 = 56562

Vậy x = ...