1.When a pencil is partly in a glass of water, it looks as if it____.
A. breaks B. has broken
C. were broken D. had been broken
2.I insisted _____to see a doctor, but he insisted nothing ___ wrong with him.
A. on him to go; should be B. he went; be
C. he go; was D. he should to; is
请详细解答，谢谢

1. C

as if 后面用表示过去时或过去完成时的虚拟语气。这句中，因为是表示现在或目前的状况，所以be broken要用成过去时形式。
参考：He talks as if he had been to America.这句中用过去完成时 had been to ，是因为表示过去去过似地，与过去相反，所以采用过去完成时.
2. C

句中第一个insist表示 “坚决要求，坚决主张，坚持”，后面搭配on doing 或者that+ sb should do 虚拟语气。

句中第二个insist表示 “坚持宣称，坚决认为”，相当于以前所学的think，suppose等，后面不用虚拟语气。