You must set off at once you would be late for school.A. thenB. and C. otherwise D. so

问题补充：

You must set off at once, you would be late for school.

A. then

B. and

C. otherwise

D. so

答案：

A. then

B. and

(答案→)C. otherwise

D. so

解析：考查连词的用法。句意：你必须马上出发，否则的话你就会上学迟到的。Otherwise否则，要不然。