When we saw the road ______ with snow, we decided to spend the holiday at home.
The conference has been held to discuss the effects of tourism ______ the wildlife in the area.
.Wait till you are more ______. It’s better to be sure than sorry.
.She will tell us why she feels so strongly that each of us has a role ______ in making the earth a better place to live.
.He suddenly saw what looked like a snake in the darkness. For an instant his heart seemed to stop ______.
I can think of many cases ______ students obviously knew a lot of English words and expressions but couldn't write a good essay.