腿部深、浅静脉血栓形成的治疗不同之处在于前者需：（） A.卧床休息 B.抬高患肢 C

Bats are amazing animals. There are many kinds of them. Most bats are black or grey in colour. And they have wings, too. Many people believed that bats couldn’t see. In fact, Bats can always find their way around very well. Usually, bats live in caves and trees. They can fly to their homes from far away. Some scientists said, “Bats can see with their ears.” Is it right? Most bats make a sound. The sound is too low for our ears to hear. They screech（尖叫） when they move around, and the echoes（回声）of these cries come back to their ears. In this way, they are able to tell where walls and other things are. Bats go out to eat at night. In the daytime they hang close together in their caves, trees or other dark places. Only when evening comes，they begin to come out and look for food, In the morning they come home to sleep until the next night. Some people think of bats as bad animals. In fact, they are very useful animals. Most of them catch bad insects（昆虫）for food. Some bats eat flowers and fruit as well.

Appearance	They are  76  or grey and have  77 .
Homes	Most bats live in 78  and   79  .
Diet	Most bats eat 80 and some may eat flowers and  81.
Lifestyle	They  82  in the daytime and look for 83  during the night.
How they find ways	They “see” with their  84  because they can make a  85  that we can’t hear.