常用句式（三）

For the past+时间，subject+现在完成时

E.g.

For the past two years,I have been busy preparing for the examination.

过去两年来，我一直忙着准备考试。

Since+subject+过去式，subject+现在完成时

E.g.

Since he went to senior high school,he has worked very hard.

自从他上高中，他一直很用功。

It pays to +verb.~   ……是值得的

E.g.

It pays to help others.

帮助别人是值得的。

Be based on   以……为基础

E.g.

The progress of the society is based on harmony.

社会的进步是以和谐为基础的。

spare no effort to +verb,  不遗余力的

E.g.

We should spare no effort to beautify our environment.

我们应该不遗余力地美化我们的环境。