A. you have joined B. have you joined C. you have been in D. have you been in 【答案】C
【解析】考查时态。句意：你能告诉我你在海军服役多长时间了吗？现在完成时态和一段时间连用，谓语动词用持续性动词，故答案为C。
6. The workers insisted that they ______ a free lunch every noon, and the boss had to give in.
A. are given B. being given C. will be given D. be given 【答案】D
【解析】考查动词时态和语态。在本句中insist是“坚持要求”，应该用虚拟语气,“should + 动词原形” 省略should。另外they和give之间是被动关系，可知答案为D。 【名师点睛】 insist
1.意思是“坚持要”表示命令、要求,其后之宾语从句要用虚拟式动词原形
或者“should + 动词原形” 例：They insisted that she (should) be invited.这种虚拟语气的用法除了“insist”还有：demand,suggest,order,propose.
2.意思是“坚持说,硬说”,其后宾语从句用普通时式,不用虚拟语气。例：She insisted that he was wrong.
7. — I don’t understand why you didn’t go the lecture yesterday afternoon? — I am sorry. But I _________ my homework. A. was doing B. had done C. would do D. am doing 【答案】A
【解析】考查动词时态。根据语境，对话中的第二个人昨天下午没去听课，而是在做作业，故使用过去进行时态，表示过去一段时间内在持续发生的动作，故选B。
8. The palace caught fire three times in the last century, and little of the original building _______ now. A. remains B. is remained
C. is remaining D. has been remained