从A、Ｂ、Ｃ、Ｄ四个选项中，选出填入空白处的最佳选项，在答题卡上将该选项涂黑。
21. As ______ unemployment is very high at the moment, it’s very difficult for people to find
______work.
A. the；/ B. /； / C. the； a D. an； the
22. — Who is making so much noise in the garden?
— ______ the children.
A. It is B. They are C. That is D. There are
