Câu hỏi:

Đọc đoạn văn và chọn đáp án đúng nhất bằng cách khoanh tròn A, B, C hoặc D tương ứng cho mỗi câu dưới đây. 

Have you ever entered a tropical rainforest? It's a special, dark place completely different from anywhere else. A rainforest is a place where the trees grow very tall. Millions of kinds of animals, insects, and plants live in the rainforest. It is hot and humid in a rainforest It rains a lot in the rainforest, but sometimes you don’t know it’s raining. The trees grow so closely together that rain doesn’t always reach the ground. Rainforests make up only a small part of the Earth's surface, about six percent. They are found in tropical parts of the world. The largest rainforest in the world is the Amazon in South America. It covers about five million square kilometers. There are also rainforest in Western Africa, Central America, Southeast Asia, Northeastern Australia and the Pacific Islands. Rainforests provide us with many things. In fact, the Amazon Rainforest is called the "lungs of ourplanet” because it produces 20% of the world's oxygen. In the rainforests, we can see half of the world’s species of animals, plants and insects. Furthermore, 80% of the food we eat first and 2S% of the drugs we take come from rainforests. Some of these drugs are even used to fight and cure cancer. With all the good things rainforests give us. it’s surprising to find that people are destroying them. A lot of trees ore being cut - down and countless valuable species are being driven to the extinction. It creates many problems worldwide such as more pollution, less rain, and less oxygen for the world.

 What is the main idea of the passage?