31．It was not until 1920 ______ regular radio broadcasts began．

　 　 A．while　　　　　　　　　 B．which　　　　　　　　 C．that　　　　　　　　　　 D．since

30．_______ you diet and take more exercise ______ be able to keep fit．

　 　 A．Only if , you will　　　　　　　　　　　　　　　　 B．Only if, will you　

C．Unless, will you　　　　　　　　　　　　　　　　　 D．Unless, you will

29．As nobody here knows what is wrong with the machine, we must send for an engineer to _____ the problem．

　 　 A．handle　　　　　　　　 B．raise　　　　　　　　　　 C．face　　　　　　　　　　 D．present

28．My brother was so _______ reading the novel that she didn’t realize the food had got bad．

　 　 A．absorbing　　　　　　 B．absorbing in　　　　 C．absorbed in　　　　　 D．absorbed to

27．---The lights were left on all night long．

　 ---Yes．It seems that Tom is ______．He was the last one who left the classroom yesterday evening．

　 　 A．blaming　　　　　　　 B．blamed　　　　　　　　 C．to be blamed　　　　 D．to blame

26．______ her nose, Mary is a beautiful girl．

　 　 A．Besides　　　　　　　 B．Apart from　　　　　 C．Except that　　　　　 D．Now that

25．The band around the corner was robbed last night．The police are now ______ the matter．

　 　 A．looking after　　　　 B．looking for　　　　　 C．looking into　　　　 D．looking out

24．The professor told us that his conclusion was based ______ his further research about that then．

　 　 A．on　　　　　　　　　　　 B．about　　　　　　　　　 C．for　　　　　　　　　　　 D．above

23．______ delighted me most was ______ my daughter was admitted to Beijing University．

　 　 A．That, what　　　　　 B．What, that　　　　　 C．What, what　　　　 D．That, that

22．Finding her car stolen, _________．

　 　 A．a policeman was asked to help

　 B．the area was searched thoroughly

　 　 C．it was looked for everywhere

　 D．she hurried to a policeman for help