根据句意及首字母提示完成下列句子

1. The boys often help the old man c_____water and sweep the floor.

2. I come here s _____ to ask you a question.

3. The glass is f_____with water.

4.  He can't hear anything because he is d_____.

常用的润滑剂有润滑油和（）。

A、蓖麻油

B、润滑脂

C、机油

D、黄油