现在完成时所表示的动作在说话之前已完成，而对现在有影响，一般过去时表示过去发生的动作但对现在不产生影响。

现在完成时还表示动作开始于过去，持续到现在，也许还会持续下去。常用for 和since 表示一段时间的状语或so far, today, this week 等包括现在时间在内的状语。

eg. He has studied English for 5 years.

He studied English for 4 years when he was at college.

当堂检测：

用所给词的适当形式填空

(1)The trees in the storm have been moved off the road. (blow down)

(2)Can those at the back of the classroom hear me？(seat)

(3)It is one of the funniest things on the Internet so far this year. (find)

(4)I was out of town at the time，so I don't know exactly how it .(happen)

课后反思：

_____________________________________________________________________

课后训练

单项填空

1．Lady Gaga has put off her concert because of the difficulties________by the ongoing strikes.(2013·北京东城期末)

A．causing B．to cause C．to be caused D．caused

2．Thanks to the measures________by the local government, the polluted river is becoming clearer and clearer and fish have begun to show up in it.

　　 A．taking B．taken C．to take D．having taken

3．It was reported that 115 miners________in the flooded mine for eight days were pulled out alive at last.(2013·海淀模拟)

A．trapped B．being trapped

C．were trapped D．had trapped

4．-Was Mary in the office when you arrived there?

-Yes, but she________soon afterwards.

A．had left B．left C．will leave D．would leave

5．Tom________a letter to his parents last night, asking what had happened.

A．wrote B．has wrote C．was writing D．will write