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。

---It's burning hot today,isn't it?

---Yes,_____yesterday.

So was it

So it was

So it is

So is it

句意：“今天太热了，是不是？”“是呀，昨天也一样”。如果表示前面所说的肯定情况也适合于另一者，要用“so+助动词/情态动词/系动词+主语”。

---I think you are different now.

---Of course，times have changed and________.

so have I

so I have

neither have I

neither I have

肯定的陈述句后，跟so+主语+谓语，表示强调：确实…，其主语与前陈述句的主语相同；肯定的陈述句后，跟so+谓语+主语，表示…也…，其主语与前陈述句的主语不同．根据times have changed，可知对另一个"我"说时代也已经变了，用倒装句，本句是现在完成时，含有助动词have，主语为I，在这里还用助动词have完成，故选A．

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。

The law           equal rights for men and women.

permits

confirms

persevers

guarantees

考查动词辨析。句意：这个法律确保了男女权利平等。A.permit允许；B.confirm证实，证明；C.persever坚持；D.guarantee保证，担保。分析句意可知，空格处为动词做谓语，其主语为the law,为单数则谓语动词用第三人称单数形式。又因the law作用是保证公平。故选D项。