_____ to sunlight for too much time will do harm to one’s skin.
| A．Exposed | B．having exposed |
| C．Being exposed | D．After being exposed |
15. The factory _______ large numbers of tractors to the peasants.
| A．provides | B．supplies | C．ensures | D．stores |
14. The teacher insisted _______ until we finished the work.
| A．we not rest | B．on our resting | C．we rested | D．we would not rest |
13. — How do you keep fit?
— By having a healthy diet and _________ regularly.
| A．turning out | B．working out | C．giving out | D．going out |
12. Having finished their morning work, the clerks stood up behind their desks, ________ themselves.
| A．expanding | B．extending | C．expressing | D．Stretching |
11. ________ no need for us to discuss the problem again. It has already been settled.
| A．It has | B．There is | C．It is | D．There has |