1580    nhá bn 

1/I cry when my test scores are low

Các trang có 1 chữ số từ 1 đến 9 có:    9 - 1 + 1 = 9 (trang)
Các trang có 2 chữ số từ 10 đến 99 có:    99 - 10 + 1 = 90 (trang)
Để trung bình cộng mỗi trang có 2 chữ số thì số trang có 3 chữ số phải bằng số trang có 1 chữ số.
Tổng số trang của quyển sách là:   9 + 90 + 9 = 108 (trang)
            Đáp số:  108 trang

1/  I got the best score

Environment is an essential part of our life. A clean environment is necessary for a peaceful and healthy life. An environment is the natural surroundings which helps human beings, animals and other living things to grow and develop naturally. But nowadays, our environment is disturbing in many different ways. Any type of disturbance in nature's balance affects the environment totally. It does not only ruin human lives but also affects all living beings. We can save our environment with the little step taken by everyone on the earth. We should reduce the amount of waste, throwing wastes properly to its place only and many other simple ways. It is very important to save the environment for human existence. When we protect the environment, we are protecting ourselves and our future as well.   Đây nha bn