15、It is time + S + 过去式
(该是……的时候了)
例句：It is time the authorities concerned took proper steps to solve the traffic problems.
该是有关当局采取适当的措施来解决交通问题的时候了。
16、Those who ...
(……的人……)
例句：Those who violate traffic regulations should be punished.
违反交通规定的人应该受处罚。
17、There is no one but ...
(没有人不……)
例句：There is no one but longs to go to college.
没有人不渴望上大学。
18、be + forced/compelled/obliged + to + V
(不得不……)
例句：Since the examination is around the corner， I am compelled to give up doing sports.
既然考试迫在眉睫，我不得不放弃做运动。
19、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。
20、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.
夏天很闷热。那就是我不喜欢它的原因。