Make sentenses using the following prompts example: this problem | for too long they have been trying to solve this problem for too long 1. the presentation | several days 2. the custimers | twenty minutes 3. this conference | two weeks 4. this fax | 7 o'clock 5. this subject | three terms 6. the lecture | two hours 7. the perfomance | several month 8. training | one year

1. They have been preparing the presentation for several days .

2. The customers have been waiting for twenty minutes .

3. They have been this conference for two weeks .

4. They have been waiting for this fax since 7 o'clock .

5. We have been studying this subject for three terms .

6. They have been listening to the lecture for two hours .

7. We have been preparing the performance for several month s.

8. He has been training for one year.