You have to wear a helmet and a life jacket for protection, just ___ you fall into the water.A. in case C. unless C. though D. as
He has known the truth. Therefore, there is no ____ to keep it a secret
In China, a good many traditional customs have____.
---May I go to the cinema this evening?---____. We should do the voluntary work in the nursing house.
It is dark outside, so please____ your step while going down the stairs.
I’m not a little hungry now, but I____ enough at lunch.