48. American scientists invented the computer in the middle 20th c_•

6. He was_ tired_ he couldn’t go on working.

A. too； to    B.    such； that

C. so； that    D.    too； that

5.    It took me two hours_ my homework last night.

A. to finish    B.    finishing

C. finished    D.    for finishing

4.    What about_ the hill?

A. climb up    B.    to climb up

C. climbing up    D.    to climb

3. If you work hard, you_ pass the exam.

A. are able to    B.    will are able    to

C. be able to    D.    will be able    to

2.    Don’t_jeans  to  school,  _your teacher won’t let you in.

A. put on； and    B.    put on； or

C. wear； and    D.    wear； or

1. This letter is about how_ English    well.

A. to learn    B.    learn

C. learning    D.    learned

15. We had a great time playing football, (have a great time doing sth.)

造句:他们在公园划船玩得很开心。_

14. Let’s have it today. (Let's /Let’s not do sth.)

造句：咱们今天别出去了吧。_

13. It’s best not to run away from our problems. (It’s adj. (for sb. ) not to do sth.)

造句:在家不惹父母不开心是最好的了。_