---Who was calling you on the phone just now？

---_______.

That's him

It was Tom

This was someone

Maybe Jim's

考查强调句。句意---刚才谁在电话里面叫你？---他是汤姆。根据题意，答句为强调句。完整形式为it was Tom that call you on the phone just now.缩写形式为It was Tom，故选B。

Only after my friend came ______.

did the computer repair

he repaired the computer

was the computer repaired

the computer was repaired

句意：直到我的朋友来了之后电脑才被修理。放于句首的only修饰时间状语从句after my friend came，主句应进行部分倒装，将助动词was提到主语前面，故选C项。

All we need          a piece of advice on how we can improve our time management.

are

is

were

was

考查be动词和时态。句意：我们需要的只是一条关于如何改进时间管理的建议。分析句子可知，说明一般情况应该用一般现在时，这句话的主语是All we need, 所以为主语从句，当主语从句作主语时，谓语动词用单数，所以用is。故选B项。

It has been warned that        to the surroundings with people infected by Covid-19 without any

protection can lead to severe result.

being exposed

exposed

having exposed

to expose

考查非谓语动词。句意：有人警告称，在没有任何保护措施的情况下，暴露在有感染 Covid-19的人环境中会导致严重的结果。分析句子结构可知expose在句中应用非谓语动词形式，表示“暴露”短语为be exposed to,且从句中缺少主语，expose 与主语people是被动关系，故应用动名词的被动式作主语。故选A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。

So difficult __________ it to work out the problem that I decided to ask Tom for advice.

 I did find 

did I find

 I have found  

have I found

句子使用的基本句式为so…that…结构。按英语语法，当该结构的so…置于句首时，其后的句子(主句)要用倒装语序，如：So loudly did he speak that even people in the next room could hear him. 他讲话声音那么大，隔壁屋里的人都听得见。