第028句

If the letter to be mailed was placed on the writing table an hour ago, it is certain to be there now.

译文：如果那封要寄的信一个小时前是放在写字台上的，那它现在肯定还在那儿。

点睛：在if引导的条件状语从句中，to be mailed为letter的后置定语，表示将来的概念。该题考查不定式的用法，当certain在句中作表语，表示“一定会...”时，其后要跟动词不定式或that引导的从句。

He is certain to win the game.
他一定会赢得比赛。
He is certain that they will win the game.
他认定他们将赢得比赛。

考点归纳：将来时的表达方式：

*be going to do

It's going to rain。
要下雨了。

*be about to do

They’re about to leave．
他们就要走了。

*be to do

You are not to smoke in the office.
你不能在办公室里抽烟。