1．构成：have / has + been + 现在分词
（1）表示从过去某时开始发生，一直延续到现在且可能延续下去的动作。 （最好将此定义读 5遍）
►. I"ve been waiting for an hour but she hasn"t come.
►. He has been running after her for 8 years.
►. I"ve been wanting to see you for so many years.
►. Who"s been telling you such nonsense.
►. I have thought of it.（我已想到了这一点。）
►. I have been thinking of it.（我一直在想这一点。）
►. Jim has painted the door.（杰姆已将门油漆过了。）
►. Jim has been painting the door.（杰姆一直在油漆门。）
1. They ________ us since five o"clock this morning.
A. are helping B. have been helping
C. have been helped D. have helped
2. I ________ the book the whole day, yet I haven"t finished it.
A. have been reading B. have read
C. am reading D. had been reading
3. Please come in. We ________ about your paper.
A. talk B. had been talking
C. have been talking D. would have talked
4. Such natural resources as coal and petroleum ________.
A. gradually are exhausted B. are being gradually exhausted
C. have gradually exhausting D. have been exhausting gradually
5. It ________ almost every day so far this month.
A. is raining B. rained C. rains D. has been raining
1. You should go to bed. You ________ (watch) TV for 5 hours.
2. I ________ (write) letters since breakfast.
3. I ________ (write) 3 letters since breakfast.
4. Sorry, but Mr. Smith ________ (leave) for Beijing.
5. I ________ (look) for him everywhere, where can he be?
1. B 2. A 3. C 4. B 5. D
1. have been watching 2. have been writing
3. have written 4. has left
5. have been looking