21 How long_at this job?-Since1990A.were you employed B.have you been employed C.had you been empoloye D.will you be employed22 I want to busy that kind of cloth because i _ the cloth _well.A.have told ,washes B.have been told ,washes C.was told ,washed D.have been told ,is washed30 The door_.Better have it repaired.A.isn't shut B.hasn't been shut C.isn't been shut D.won't shut19 He knew that all his classmates_the exam except him.A .has passed B.have

21、—How long _ atthis job?—Since1990.
　　【选择】B.have you been employed
　　【解析】把问话和回答连在一起就是 How long _ at thisjob since1990?回答中的 since1990意思是指“从1990年到现在”,因此要用现在完成时.
22、I want to buythat kind of cloth because I _ the cloth _well.
　　【选择】B.have been told ,washes
　　【解析】从上文的一般现在时 want to buy 可以看出句子的立足点是现在,因此 C 项的过去时不在选择之列.由于这种布经洗是被告知的,所以 A 项的主动语态应该排除.表示“耐洗” wash 是不及物动词,故 D 项的被动语态 is washed 也应排除.
30、The door_.Betterhave it repaired.
　　【选择】D.won't shut
　　【解析】“门关不上”是门自身的问题,而不是由人操作的,况且 beshut 意思是“门被关上了”,因此A.isn't shut 意思是“现在保持着关上的状态”,B.hasn't been shut 表示“还没有被人关上”,C.isn't been shut 表示“现在总是被人关”.故此,这里需要用不及物的 shut.
19、He knew thatall his classmates _ the exam except him.
　　【选择】C.had passed
　　【解析】主句 he knew 是过去时,宾语从句的时态要与主句保持一致.A.has passed 和 B.have passed都是现在完成时,况且A 项的人称形式 has 也不对；D.would have passed 是对现在的虚拟语气,意思是“本来是会及格的”,言外之意是现在已经通过了,不仅与主句的时态也不一致,而且意思也变成了除了他以外全班同学本来都会及格,也就说除了他以外全班人这次都不及格