Some pre-school children go to a day care center, __________ they learn simple games and songs.
| A．then | B．there | C．while | D．where |
Every few years, the coal workers ___________ their lungs X-rayed to ensure their health.
| A．are having | B．have | C．have had | D．had had |
If our parents do everything for us children, we won’t learn to depend on___________
| A．themselves | B．them | C．us | D．ourselves |
Sean has formed the habit of joggingthe tree-lined avenue for two hours every day.
| A． | between | B． | along | C． | below | D． | with |
That is the only way we can imaginethe overuse of water in students' bathrooms.
| A． | reducing | B． | to reduce | C． | reduced | D． | reduce |
（北京卷28）. It took me a long time before I was able to fully appreciate what they __ for me.
| A．had done | B．did | C．would do | D．were doing |