I. Chọn một từ thích hợp trong ô dưới đây điền vào mỗi chỗ trống để hoàn thành đoạn văn sau.
too from have to live is
We are all slowly destroying the earth. The sea and the rivers are (26) dirty to swim in. There (27) so much smoke in the air that it is unhealthy (28) in many of the world’s cities. In one well-known city, for example, the gases (29) cars pollute the air so much that traffic policemen (30) to wear oxygen masks.
