The clock was striking twelve ______ down the street.
| A．because I walked | B．as I walked |
| C．since I was walking | D．while I was walking |
Everyone was in silence, having nothing to do but _________.
| A．to wait | B．wait | C．waiting | D．waited |
_________ his work , he can’t play with his friends.
| A．Not finishing | B． Finishing not | C． Not finish | D． Not finished |
All I have to do is _________my life .
| A．to enjoy | B．enjoy | C． having enjoyed | D． enjoyed |
When _______ homework , you should be careful .
| A．do | B． to do | C．doing | D． done |
_______ the news, they are very happy.
| A．Hearing | B．Heard | C．Hear | D． To hear |