It was not until 1920 ___ regular radio broadcasts began.

when

which

that

since

此题考查强调句。句意为：直到1920年，常规的电台才开始。这句话把it is/was和that去掉后，仍是完整的一句话，因此我们可以知道这是一个强调句，而且是对not...until“直到...才”的强调。结构是：it is/was+not until+其他成分。故选:C.

"Society" is a(n)              term;it may mean much or nothing.

autonomous

ambiguous

fragrant

fragile

考查形容词词义辨析。句意：“社会”是一个模棱两可的词；它可能意味着很多，也可能没有意义。autonmous 自治的；ambiguous模棱两可的；fragrant芳香的；fragile脆弱的。结合后文it may mean much or nothing可知，空格处填ambiguous模棱两可的。故选B项。

Lucy tried to help, but she was          as if she was  interfering, not helping.

dynamic

compulsory

scared

clumsy

考察形容词。句意：露西想要帮忙，但她笨手笨脚，好像在干涉别人，而不是在帮忙。A.dynamic动态的；B. compulsory 义务的；C.scared 害怕的；D.clumsy笨拙的。结合后文好像是在干涉别人，而不是在帮忙。可知露西笨手笨脚的。故选D项。

Perhaps they have experienced something similar and do not want you to           the same pain.

go over

go through

go around

go on

考查动词短语辨析。句意：也许他们有过类似的经历，不希望你经历同样的痛苦。A. go over复习，重温；B. go through经受，通过；C. go around 四处走动，流传；D. go on继续。根据the same pain可知，此处是“经历，经受”的意思。故选B项。

With a lot of difficult problems           ,he feels like a cat on  hot bricks.

to settle

being settled

settling

settled

考查非谓语动词。句意： 因为有一大堆难题要解决，他感觉像像热锅上的蚂蚁。本句with +名词+to do sth,动词不定式表示的动作尚未发生或当时看来尚未发生。本句表示“因为有一大堆难题要解决”。故选A项。