We must keep our room clean. Dirt and disease go _____, you know.
| A．from time to time | B．hand in hand |
| C．step by step | D．one after another |
_____ with so much trouble，we failed to complete the task on time．
| A．Faced | B．Face |
| C．Facing | D．To face |
________ around the Water Cube，we were then taken to see the Bird’s Nest．
| A．Having shown | B．To be shown |
| C．Having been shown | D．To show |
I have ______ all the papers but I still can’t find my notes．
| A．looked for |
| B．looked through |
| C．looked after |
| D．looked out |
_____in the sports world，a sportsman needs to train constantly to keep himself in best condition．
| A．Survive | B．Surviving | C．To survive | D．Survived |
Teenagers ________ their health because they play computer games too much．
| A．have damaged |
| B．are damaging |
| C．damaged |
| D．will damage |