粘弹剂在眼科手术中的作用主要包括（）。

A.产生并维持空间，便于手术操作

B.保护角膜内皮细胞

C.帮助止血

D.帮助恢复前房，维持眼内压

E.以上选项均正确

根据句意和所给首字母提示完成句子。

1. The increasing population may be the greatest c________ of the world today.

2. Will it b________  you if I turn the television on?

3. He is an e________ boy,  he enjoys sports.

4. Peter is c________ of winning the post as the assistant to the managing director.

5. The old woman felt n________ as she tried to cross the busy road.

1.______ 2.______ 3.______ 4.______ 5.______