4. mercy n. 仁慈；宽恕；怜悯

show mercy to sb/have mercy on sb 对某人怜悯、仁慈

at the mercy of 任...处置；无能为力

without mercy 毫不留情地，残忍地

例句：They showed mercy to their enemies. 他们对敌人很仁慈。

The ship was at the mercy of the storm. 那只船在暴风雨中失去控制。

高手过招

①He went down on his knees and_____________. 他跪下来，乞求宽恕。

②They _____________ the poor father and daughter. 他们不怜悯这对可怜的父女。have no mercy on

③I shouldn't like to be ____________ such a cruel man. 我不想任由这个残忍的家伙摆布。

④ _________________ she wasn't seriously hurt. 幸运的是她伤势不重。

答案：begged for mercy、have no mercy on、at the mercy of、It is a mercy that

5. certain adj. 确定的；某一；一定

for certain确定的，确实的 make certain弄清楚，弄确实

be certain to do 一定会做某事 be certain of确信...

同意辨析：certain和sure

certain的主语既可以是人，也可以是物，而sure的主语通常为指人的词。

即景活用

(1) There is ________ at the door who wants to speak to you.

A．some men B．a some man C．certain men D．a certain man

解析：答案D。由there be句型中的is可知空中应用单数名词；而some与单数名词连用时，不用a。some man＝a certain man"某个人"。

(2 ) It is ________ that the Chinese ping－pong team will win the prize.

A．sure B．necessary C．regular D．certain

解析：答案D。It is certain that...确信......。句意为：看来中国乒乓球队有得奖的把握。

6. contain vt. 包含；容纳