He has run 3 miles. （强调跑完的距离）

He has been running for an hour. （强调动作和结果，如：过去的一个小时干了什么，以及现在为什么这么累）

3. 现在完成时和时间状语

现在完成时一般使用下列时间状语：before, ever, never, seldom, sometimes, often, usually, just

其中，already用于陈述句中，一般放在have后；yet用于疑问和否定句中，通常放在句末。例如：

I have already repaired my bike.

Have you repaired your bike yet?

I haven't repaired my bike yet.

关于for和since

for用于说明动作的时间长度，例如：

I haven't seen him for ten years.

since用于说明动作的起点，例如：

I haven't seen him since 1990.

1. -I'm sorry, but I don't quite follow you. Did you say you wanted to return on September 20?

-Sorry, I________ myself clear. We want to return on October 20.

A．hadn't made B．wouldn't make C．don't make D．haven't made

2. We ________on this project for four hours. Let's have a rest.

A. are working B. have been working C. worked D. had worked

3. Shakespeare's play Hamlet _________ into at least ten different films over the past years.

A. had been made B. was made C. has been made D. would be made

4. --- So what is the procedure?

--- All the applicants _________ before a final decision is made by the authority.

A. interview B. are interviewing

C. are interviewed D. are being interviewed

5.Now that we ____ all the money, it's no use turning on me and saying it's all my fault.

A. had lost B. lost C. have lost D. lose

基础演练

一. 单选

1. The twins, who their homework, were allowed to play badminton on the playground.