______about wild plants that they decided to make a trip to Madagascar for further research.

So curious the couple was

So curious were the couple

How curious the couple were

The couple was such curious

It was the typhoon           was called Tiange           hit Zhuhai and Macao.

which; that

what; which

that; who

that; which

考查定语从句和强调句型。句意：袭击珠海和**的是“天阁”的台风。此处typhoon是先行词，指物在后面的定语从句中做主语，所以第一空填which/that；第二空是强调句句型，It is/was+强调部分+that（指人也用who）+其他，这里typhoon指物。所以第二空填that。故选A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。