A: Hey, Ginny. What do you call those big, gray things in the water? 　　
B: 1______. 　　
A: What? 　　
B: Manatees. They're very gentle and very shy. 　　
A: 2______? 　　
B: They're usually about 10 feet long and they weigh about 1000 pounds. 　　
A: How much do they need everyday? 　　
B: They need about 1 00 pounds of aquatic food a day. 　　
A: 3______? 　　
B: It is underwater plants and vegetation (植被). 　　
A: That's what they eat? 　　
B: Yes. it is. 　　
A: 4______? 　　
B: Yes, they are endangered (陷入困境). But, we're trying to save them. 　　
A: Wait a moment. Why are they endangered? 　　
B: 5______. 　　
A: Where do they live? 　　
B: They live in the swamps (沼泽). 6______.They are endangered also because there sometimes
    isn't enough food for all of them. 　　
A: 7______. There used to be a lot of manatees, but now there aren't very many ofthem left, I think. 　　
B: Yes, 8______. At this point, there are only about 2,500 in the U.S. 　　
A: 9______? 　　
B: Since 1927 laws have been passed to protect them. 　
A: Thank you for your information. 　　
B: 10______.