患者女性，37岁。触电倒地后神志丧失，呼吸不规则。

提示：确诊患者发生了心跳骤停，立即进行心外按压和人工呼吸。单人进行复苏时心外按压与人工呼吸的比例是（）

A.1：1

B.2：1

C.5：1

D.10：1

E.15：1

F.15：2

根据句意，用括号内所给单词的适当形式填空。

1. I like P.E. best. Because my P.E. teacher is very _______ (friend) to us.

2. —Where is your bedroom?  —It's on the ________ (three) floor.

3. —Thank you for your help.       —It's my _______ (please).

4. All the books are on these _______ (shelf). You may go to find the book you want to borrow.

5. Kangkang likes _______ (dance) at the party, because it's interesting.