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，并在答题卡上将该项涂黑。
21. The color green in ancient Egypt symbolized spring, which is the time of _______ year when things in nature start to grow after _______ long winter.
A. /; a B. the; the C. /; the D. the; a
22. China needs to strike a balance between maintaining a ______ fast and stable development and economic structural adjustment.
A. relatively B. seemingly C. approximately D. environmentally
23. The first thing you must remember is that in order to succeed, it is almost compulsory that you ______ be optimistic.
A. must B. will C. need D. should
24. — Do you know why Michael resigned from the board?
