问题
The directors have a meeting every Friday ______ there is nothing to discuss.
A:unless
B:because
C:when
D:if;
B:because
C:when
D:if;
正确答案是：
同类题型
The reason _____ their failure you know is ______ they didn’t get fully prepared for the experiment.
Tommy, you should be reading your Maths right now.— I know I ________.
77Oh, sorryA lighted cigarette burned a hole _____ my coat, and I have to change another one
The astronauts started their journeys in rockets _____forward by jets of hot gas.