There's no simple solution          this problem.

of

for

to 

about

考查介词。句意：这个问题没有什么简单的解决方法。此处是短语“

the solution to....的解决方法”，应用介词to。故选C项。

Based on the agreement,all payments          be made by the end of the month.

may

can

shall

will

考查情态动词。句意：根据协议，所有款项应在月底付清。shall用于法律，条款中表示必须要做的事。故选C项。

I drink a cup of coffee           ; but usually I take tea.

frequently

often

constantly

occasionally

考查副词词义辨析。句意：我偶尔喝一杯咖啡，但我通常喝茶。A. frequently频繁地；B.often经常地；C.constantly连续不断地；D.occasionally偶尔地。but 表转折关系；根据后半句的usually,前面用occasionally,与usually意思相对。故选D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。