I think it           that she should be knowledgeable about Music for her present job.

urgent

normal

essential

gifted

考查形容词词义辨析。句意：我认为她对音乐的了解对她目前的工作是必要的。A. urgent紧急的；B. normal普通的；C. essential基本的、必要的；D. gifted有天赋的。根据句意以及后接宾语从句为

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.

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。

In our daily life, everyone fails every now and then. It is how you             that makes a difference.

react

replace

rely

request

考查动词词义辨析。句意：在我们的日常生活中，每个人都会时不时地失败，你对失败如何反应才是关键。A. react反应；B. repalce取代，代替；C. rely 依靠，依赖；D.request要求；根据“n our daily life, everyone fails every now and then”，应是“怎样做出反应”。故选A项。

Like other animals, we are          until we know it is safe to relax.

on purpose

on fire

on guard

on duty

考查介词短语辨析。句意：像其他动物一样，我们在知道安全的时候才放松警惕。A.on purpose 故意；B. on fire着火；C.on guard 警惕；D.on duty值班。结合后文we know it is safe to relax，可知我们在知道安全的时候才放松警惕。故选C项。

Great amounts of water            poured into the river from the factories two years ago.

was

were

has been

have been

考查时态和主谓一致。句意：两年前，工厂将大量废水排入河中。根据two years ago 可知，句子使用一般过去时。....amounts of修饰不可数名词作主语时，谓语动词用复数形式，即谓语动词与amounts保持数的一致。故选B项。

Let's learn to use the problem we are facing         a stepping-stone to future success.

to

for

as

by

考查介词词义辨析。句意：让我们学会把我们所面对的问题作为通向未来成功的手段来利用。A.to朝，对 ；B.for 为了，对于；C.as 作为；D.by通过，凭借。根据句意可知，此处“作为”符合语境。故选C项。