38.The task is hard the workers managed to finish it in time.A. thereforeB. otherwiseC.

问题补充：

38.The task is hard, , the workers managed to finish it in time.

A. therefore

B. otherwise

C. however

D. yet

答案：

A. therefore

B. otherwise

(答案→)C. however

D. yet

解析：however 作可是解时，含义同but，前者有逗号相隔，后者后面没有逗号，前面可好可无。