定语从句练习：找出正确选项并把句子译成汉语
21.The letter is from my sister,______is working in Beijing.()
A.which B.that C.whom D.who
22.In our factory there are 2,000 workers,two thirds of ____are women().
A.them B.which C.whom D.who
23.You're the only person ______I've ever met ______could do it.()
A.who;/ B./; whom C.whom;/ D./; who
24.I lost a book,______I can't remember now.()
A.whose title B.its title C.the title of it D.the title of that
25.Last summer we visited the West Lake,______Hangzhou is famous in the world.()
A.for which B.for that C.in which D.what
26.I have bought such a watch _______ was advertised on TV.()
A.that B.which C.as D.it
27.I can never forget the day _______ we worked together and the day ______ we spent together.()
A.when; which B.which; when C.what; that D.on which; when
28.The way ______he looks at problems is wrong.()
A.which B.whose C.what D./
29.This is the reason ______he didn't come to the meeting.()
A.in which B.with which C.that D.for which
30.This machine,______for many years,is still working perfectly.()
A.after which I have looked B.which I have looked after
C.that I have looked after D.I have looked after