十九、It is conceivable that+句子(可想而知的);It is obvious that+句子(明显的);It is apparent that+句子(显然的)

　　例句：It is conceivable that knowledge plays an important role in our life.

　　可想而知，知识在我们的一生中扮演一个重要的角色。

　　二十、That is the reason why-(那就是……的原因)

　　例句：Summer is sultry. That is the reason why I don't like it.

　　夏天很燠热。那就是我不喜欢它的原因。

　　二十一、For the past+时间，S+现在完成式……(过去……年来，……一直……)

　　例句：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。

　　二十二、Since+S+过去式，S+现在完成式。

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

　　自从他上高中，他一直很用功。

　　二十三、It pays to+V-(……是值得的。)

　　例句：It pays to help others.

　　帮助别人是值得的。

　　二十四、be based on(以……为基础)

　　例句：The progress of thee society is based on harmony.

　　社会的进步是以和谐为基础的。

　　二十五、Spare no effort to+V(不遗余力的)

　　We should spare no effort to beautify our environment.

　　我们应该不遗余力的美化我们的环境。