II.

1. came

2. have just send 

3. has worked

4. graduated 

5. plays

6. was cooking

7. is attending

8. helping

9. found/ was walking 

10. have just finished

11. won't be

12. have you been

13. was driving/ ran 

15.gets

16. was invented/  worked/ was introduced/ became/ was used/ is found/ plays/ are manufactured

III

1. up 2. up 3. up 4. on 5. X 6. about 7. for 8. from 9. at/ at 10. about 11. in

12.on/ in 13.  on/on 14. at/of/ in 15. at

II. 1. came.      2. have just sent.     3. has worked / has been working.

    4. graduated.           5. plays.         6. was cooking.       7. is attending.

    8. Help.        9. found / was walking.        10. have just finished.

    11. am not.         12. ... have you been.     

    13. was driving / ran.            15. gets.

    16.

Nylon ....was invented.... in the early 1930s by an American chemist, Julian Hill. Other scientists ....worked.... with his invention and finally on 27 October 1938, nylon ....was introduced.... to the world. It was cheap and strong and immediately ....became.... successful, especially in the making of ladies’ stockings.
During the Second World War, the best present for many women was a pair of nylon stockings, but more importantly, it ....was used.... to make parachutes and tyres. Today, nylon ....is found.... in many things: carpets, ropes, seat belts, furniture, computers, and even spare parts of human body. It ....has played.... an important part in our lives for over 50 years. Next year, about 36 million tons of it will be manufactured.

III. 1. up.           2. down.             3. up.                4. for.                5. for.

     6. about.      7. for.                  8. from.            9. at / at.           10. about.

     11. in.          12. on/in.            13. on/on.        14. on/of/in.      15. at.