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。

---Let me help you cross the street.

---               ! I'm not that old.

Come on

No way

Take your time

Go ahead

考查情景交际。句意：---我来帮你过马路。---拜托。我还没有那么老。A. come on 可以表示鼓励，催促，加油，不耐烦等；B.No way 绝不；C. Take your time 别着急；D. Go ahead 表同意，继续。根据句意，选go ahead,可译为“拜托”。故选A项。

Last night I had just gone to bed          an odd delivery man knocked on the window of my house.

as

before

when

while

考查状语从句引导词。句意：昨天晚上，我刚刚上床睡觉突然觉得一个奇怪的送货员敲我房子的窗户。固定搭配had  done sth when表示某人刚做完某事突然.....故选C项。

When Huawei P20 came out,         people couldn't wait to buy one in our town.

thousand

thousands

thousand of

thousands of

考查数词的用法。句意：当华为P20上市时，成千上万的人迫不及待的想在我们镇上买一台。thousnad意思是“千”，其前有具体数词修饰时，用其单数形式；当其前没有具体数词修饰时，用其复数形式，且与of 连用，thousands of“成千上万的”，这里没有具体数词修饰。故选D项。

          is a pity           you didn't attend the lecture last night. It was wonderful.

What; that

It; that

What; why

It; why

考查固定句型。句意：很遗憾，你昨晚没去听讲座。那太美妙了。此处为句型“It is a pity that.....”，表示“遗憾的是....", It 作形式主语，that 引导主语从句是真正的主语，从句句意完整，成分齐全，that不做成分，仅起引导作用。故选B项。

I have no one        me. for I am a new comer here.

help

helping

to help

to have helped

考查非谓语动词的用法。句意：我没让人帮我，因为我是新来的。根据句意可知句子空格处非谓语动词作定语，用了have sb /sth to do的结构,意为“让某人做某事”。故选C项。

Going on a trip into         space must be quite         exciting experience.

/; the 

/; an

the; the 

the; an

考查冠词。句意：太空旅行是令人兴奋的经历。第一空不填，space前面不加冠词，第二空后面的experience作“经历”时是可数名词，表示“一次令人兴奋的经历"。exciting首字母的发音为元音音素，因此应填an。故选B项。