问题
The air pollution is terrible.—It will be worse _______ we take action to protect the environment.
A:if
B:unless
C:until
D:When;
B:unless
C:until
D:When;
正确答案是：
同类题型
This company was ______ of using misleading advertisements in its promotion of the weight-loss pills
That was because the school bus was _________ by athick fog.
Sandy a pretty dress. She enjoys very much.
so cold! Why are your windows stillopen — Oh, they _______．
Are your shirts made cotton—Yes, they are. And they were made the US.