dip
dip sth into sth
dip sth in
蘸；浸
He dipped the brush into the paint.
他拿画笔蘸了蘸颜料。
Dip your hand in to see how hot the water is.
把手伸进去看看水有多热。

reason
reason why...
reason that...
reason for sth
reason for doing sth
原因；理由；解释
I'd like to know the reason why you're so late.
我想知道你为什么迟到那么长时间。
We aren't going for the simple reason that we can't afford it.
我们不去,只是因为我们负担不起。

smart
聪明的；机敏的；精明的
She's smarter than her brother.
她比她哥哥聪明。
That was a smart career move.
那是个人事业发展上的一着妙棋。
OK, I admit it was not the smartest thing I ever did (= it was a stupid thing to do).
好吧,我承认那件事我办得很不漂亮。

来源:可可英语 http://www.kekenet.com/video/201709/526021.shtml