重點講解：
1. for no reason 無緣無故；莫名其妙；沒有理由；
例句：For no reason at all the two men started to laugh.
兩個人莫名其妙地開始大笑。
2. do one's utmost to do sth. 極度；極限；最大可能；
例句：He would have done his utmost to help her, of that she was certain.
他肯定會盡最大努力幫她，這一點她非?？隙ā?br />3. prevent sb. from doing sth. 阻止；制止；阻礙；
例句：Only a serious mischance will prevent him from arriving tomorrow.
只有碰上極倒霉的意外變故,他明天才會來不了。
4. hush up 隱瞞；遮掩；不讓…張揚；
例句：The crime was so base that everyone wanted to hush it up.
這一罪行如此卑鄙無恥，大家都不想聲張出去。
5. knock on 敲；擊；
例句：Please do not enter before knocking on the door.
進來前請先敲門。