问题

Many people do not realize the importance of health _____ they have fallen ill.
A:until
B:while
C:when
D:after;
B:while
C:when
D:after;
正确答案是:
同类题型
I’m sorry. I ___________ at you yesterday.— Forget it. I was also a bit out of control myself then.
What a fine day today!—Yes,but it’s a bit ________ than yesterday.
How was your examination?—It wasn’t very difficult,but it was__________long.
________atmospheric haze(雾霾天气) or smog will continue makes the public worried
His best known work that is _____ all praise can be seen in the museum.