IV. 閱讀測驗：
 32-36
         If someone asked you to name the most powerful animal in the world, which one would you choose—the lion, the tiger, or the crocodile? Well, if someone asked me, I would name a quiet, peaceful-looking animal called a beaver.
        Why? Although hunting animals like tigers are strong and dangerous, all they do is kill. But beavers? They change their environments, just like humans do! They cut down trees with their teeth, block streams with tree branches, stones, and mud, and actually make ponds! Then they build homes inside those ponds, and because now the water surrounds their homes, they are safe from wolves and other dangerous creatures. In this way, beavers transform entire forested areas into ponds and wetlands, and provide an environment where many wetland plants and animals can live. These would include tiny water fleas, beautiful lilies, and big deer called moose. The ponds and wetlands also act as filters to help clean the streams.
         A beaver looks like a mouse, but is much bigger, fatter, and cuter. It will have a big, wide tail, and rear feet that look like duck feet, which help with swimming. Beavers cannot see very well, but their senses of hearing, smell, and touch are very good. Because beavers are highly valued for their fur, humans have killed most of them over the last few hundred years. Today we have two major kinds of beavers: North American and Eurasian. We are working hard to help them grow in number once again.
【題組】32. What is the main reason the author thinks a beaver is the most powerful animal in the world?
(A) It kills other animals cruelly.
(B) It has long teeth.
(C) It changes its environment.
(D) It looks like a mouse.