21. The beef which _______ now is for the dinner party.

   A.is being cooked  B.is cooked   C.has been cooked   D.is cooking

22. The story book, _____ the cover is broken , is Mary's.

   A.of it   B.whose   C.of which   D.for which   

23. I will never forget the day _____ I joined the basketball club.

   A.which  B.that    C.on which  D.in which  

24. Sir, you ______ be sitting in this waiting room. It is for women and children only.

A. oughtn't to       B. can't          C. won't         D. needn't

25. I have got the pen , you ____________ one for me last night.

A.needn't buy              B.mustn't buy 

C.needn't have bought       D.must have bought

26. Teachers have a great _________ on students.

   A.effort   B.affect  C.afford   D.effect