请认真阅读下面各题，从题中所给的A、B、C、D四个选项中，选出最佳选项，并在答题纸上将该项涂黑。
21. Language gives us _________ ability to communicate at ___________ much higher level than any other animals.
A. an; / B. /; the C. an; the D. the; a
22. Many young people decide to leave for ____________ is a good place to live in to seek their fortune.
A. where B. what C. which D. that
23. I offered the _____________ suggestions of
