1.A football fan is _____ has a strong interest in football.

1.A football fan is _____ has a strong interest in football.
A.a thing that B.something that C.a person who D.what
2.The house,_____ was destroyed in the terrible fire,has been repaired.
A.the roof of which B.which roof C.its roof D.the roof
3.The matter _____ you were arguing about last night has been settled.
A.that B.what C.why D.for which
4.They talked for about an hour of things and persons _____ they remembered in the school.
A.which B.that C.who D.whom
5.All the apples _____ fell down were eaten by the pigs.
A.that B.those C.which D.what
6.They asked him to tell them everything _____ he saw at the front.
A.what B.that C.which D.where
7.I’ll tell you _____ he told me last night.
A.all which B.all what C.that all D.all
8.A child _____ parents are dead is called an orphan.
A.who B.who’s C.whose D.which
9.Is this the museum _____ you visited the other day?
A.that B.where C.in which D.the one
10.Is this museum _____ some German friends visited last Wednesday?
A.that B.where C.in which D.the one
11.-How do you like the book?-It’s quite different from _____ I read last month.
A.that B.which C.the one D.the one what
12.The train _____ she was traveling was late.
A.which B.where C.on which D.in that
13.The Antarctic _____ we know very little is covered with thick ice all the year round.
A.which B.where C.that D.about which
14.It’s the third time _____ late this month.
A.that you arrived B.when you arrived C.that you’ve arrived D.when you’ve arrived
15.He often helps the students _____ he thinks are not quick at their studies.
A.whom B.who C.when D.because
16.He was born in the year _____ the Anti-Japanese War broke out.
A.which B.when C.on which D.during which
17.Mr.Crossett will never forget the day _____ he spent with his various students.
A.when B.which C.during which D.on which
18.We are going to spend the Spring festival in Guangzhou,_____ live my grandparents and some relatives.
A.which B.that C.who D.where
19.The hotel _____ during our holidays stands by the seaside.
A.we stayed at B.where we stayed at C.we stayed D.in that we stayed
20.Is that the reason _____ you are in favor of the proposal?
A.which B.what C.why D.for that

C（先行词指人,关系代词用who）
A（关系代词修饰名词作定语,用所有格,因为这个名词前面有定冠词roof,所有格要用of which放在名词的后面,这里的the roof of which等于whose roof,但whose放在名词前面,不用定冠词）
A（关系代词在从句中作介系词about的宾语,about位于从句句末,可以用关系代词that）
B（先行词既指人,又指物,兼指人与物,要用that,因为that本来就既可指人,也可指物）
A（先行词前出现不定代词,或先行词本身为不定代词时,关系代词只能用that）
B（原因同上）
D（原因同上,all that相当于缩合连接代词what,但what不能引导定语从句,只能引导名词性从句）
C（关系代词修饰名词作定语时,用所有格whose）
A（visit是及物动词,关系代词that在从句中作其宾语,不用关系副词where）
A（原因同上）
C（这里用不定代词one指代book,后可以跟定语从句）
C（travel on the train,关系代词作从句中的介系词on的宾语,因为乘火车不需要弯腰进入,而是走台阶,所以用on,在介系词之后指物的关系代词,只能用which）
D（know about the novel,关系代词作从句中介系词about的宾语）
C（固定句型,that从句用现在完成时）
B（属于复合定语从句,这个大的定语从句里嵌入一个宾语从句,关系代词做的是宾语从句中的主语）
B（关系副词在从句中作时间状语,用关系副词when）
C（关系代词在从句中作spent的宾语,仍然用which）
D（关系副词在从句中作地点状语,用关系副词where,因为where被提前,所以用了完全倒装）
A（关系代词在从句中作介系词at的宾语,at放在了后面,可以省略）
C（先行词为reason,关系副词在从句中作原因状语,用关系副词why）
希望我能帮助你解疑释惑.