从A、B、C、D四个选项中，选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。
21. In China, _____private cars are getting to be _____popular means of transportation.
A. the; a B. / ; a C. the; the D. / ; the
22. ------ Sorry, I’m late.
------That’s OK. You’re here and that’s what __________.
A. does B. works C. stays D. counts
