第二节（共5小题；每小题2.5分，满分12.5分）
阅读下面短文，从短文后的选项中选出可以填入空白处的最佳选项。选项中有两项为多余选项。
Clownfish like to live in coral reefs, but they don't spend their whole lives there. In the first few months after they are born, they "wander" in the open sea. When the baby clownfish grow big enough to swim, they hurry home. They can't see the reef, however. 16.
But humans—and their ships, speedboats, energy exploration platforms and even surfing—have made the ocean an unbearably noisy place. 17. In the case of baby clownfish, they make them unable to find their way home.
18. There are still many other sea animals depending on their ability to hear for their survival. They use sounds to sense their environment and to communicate. Dolphins call one another by unique names. Tuna fish. Whales sing.
19. Many sea animals swim away from the noises. 20. _______ But slow-moving animals like sea cucumbers (海参) are left helpless. In some places, human-made noises are everywhere. Animals have to permanently move away from these noises to quieter places. They are then forced to compete with others for the same pools of resources. Over time, their populations start to become smaller.
Luckily, the noise is a controllable pollutant. "We know exactly what causes the noise, we know where it is and we know how to stop it," said Steve Simpson, a biologist in England. 21. _______ Wind-powered boats have been developed. Shipping routes can also be moved away from certain areas. Researchers are calling for stricter rules. "We have noise standards for cars and trucks," said Carlos Duarte, another biologist. "Why should we not have them for ships?"
A. Clownfish are not the only ones to suffer.
B. They stress the protection of privacy.
C. They are ignored but independent.
D. These noises are often louder than the natural ones.
E. Instead, they depend on the small noises that a reef lets out.
F. Whales, for example, can learn to avoid busy shipping routes.
G. Actually, the ocean has always been home to many clownfish.