Read the following passage taken from Microsoft Encarta and mark the letter A, B, C, or D on your answer sheet to indicate the correct word(s) for each of the blanks.
WHY DO ANIMALS GO EXTINCT?
Different kinds of animals have appeared and disappeared throughout Earth’s history. Some animals go extinct because the climate_______ (43) they live changes. The climate may become wetter or drier. It may become warmer or cooler. If the animals cannot change, or adapt, to the new climate, they die.
Some animals go extinct because they cannot_____ (44) with other animals for food. Some animals go extinct because they are killed by enemies. New kinds of animals are always evolving. Evolving means that the animals are changing_______ (45) from generation to generation. Small differences between parents, children, and grandchildren slowly add up over many, many generations. Eventually, a different kind of animal evolves.
Sometimes many of the animals on Earth go extinct at the_____ (46) time. Scientists call this a mass extinction. Scientists think there_______ (47) at least five mass extinctions in Earth‘s history. The last mass extinction happened about 65 million years ago. This mass extinction killed off the dinosaurs.
Trả lời câu hỏi dưới đây:
________(47)
Câu này hỏi về cách sử dụng thì của động từ. thì hiện tại hoàn thành diễn tả hành động xảy ra trong quá khứ và tiếp tục kéo dài đến hiện tại và tương lai
Ta cũng nên lưu ý từ “think” ở mệnh đề chính ở thì hiện tại đơn
Đáp án là C: Scientists think there have been at least five mass extinction in Earth ’s history.