9. You ________ never work too hard in learning a language. That's what it takes to learn a language well.
答案：can 解析：考查情态动词。句意：学习一门语言时你再努力也不为过，那是学好一门语言所必需的东西。can't(can never) ... too ...“再……也不为过”，符合语境及句子结构，故选B。
10. (2014·成都高中毕业班诊断性检测)—You talk so much about London. You ________ have been there.
—Yeah, I went sightseeing on a tour last summer.
答案：must 解析：考查情态动词。根据“you talk so much about London.”可知，空处应表示对过去事实的肯定推测，因此用must have done。can表示推测时常用于否定句或疑问句。
11. (2014·山东潍坊高三联考)—How about your trip to Hawaii?
—Wonderful! I ________ have enjoyed myself more.
答案：couldn't 解析：考查情态动词。根据“Wonderful”可知，此处意为“我不可能过得比那更愉快了”，暗指当时过得最愉快。“can't/couldn't ...+比较级”可表达最高级含义。
12. (2014·福建福州高三质量检测)—What if you ________(forget) to send all essay with your application?
—I would have been rejected.
答案：had forgotten 解析：考查虚拟语气。句意：“如果你在寄申请的时候忘记发送一篇论文会怎么样?”“我会被拒绝的。”根据答语可知，问句表示对过去事实相反的假设，故应用过去完成时。
13. The constant rise of meat price requires that effective measures ________(take) by the government.
答案：be taken 解析：考查虚拟语气。句意：肉价的持续上涨要求政府采取有效措施。require后的宾语从句要用虚拟语气，be taken前省略了should。
14. (2014·北京海淀区高三期末)But for the mistakes he made, Li Ming ________(pass) the entrance exam last year.
答案：would have passed 解析：考查虚拟语气。句意：李明要不是在去年的入学考试中犯了那些错误，他原本可以通过考试的。由“But for”和“made”可知，这里表示与过去事实相反的假设，谓语应用“would have+过去分词”。
15. (2014·北京东城区高三检测)—Do you like the school?
—Yeah. I only wish the classes ________(be) a little smaller.
答案：were 解析：考查虚拟语气。句意：——你喜欢这个学校吗?——是的。我只希望我们的班级小一些。在wish后的宾语从句中，谓语动词要用虚拟语气，此处表示对现在情况的一种假设，谓语动词要用过去式。
