After the fierce competition, the students were taken to their camp, _____ they would rest for next round．
| A．where | B．who | C．which | D．what |
The water ________ cool when I jumped into the pool for morning exercise.
| A．was felt | B．is felt | C．felt | D．feels |
—What's that noise?
—Oh，I forgot to tell you.The new machine ________.
| A．was tested | B．will be tested |
| C．is being tested | D．has been tested |
—Why does the lake smell terrible?
—Because large quantities of water ________.
| A．have polluted | B．is being polluted |
| C．has been polluted | D．have been polluted |
His sister left home in 1998，and ________ since.
| A．had not been heard of | B．has not been heard of |
| C．had not heard of | D．has not heard of |
In the near future，more advances in the robot technology ________ by scientists.(2011·湖南)
| A．are making | B．are made |
| C．will make | D．will be made |