第一部分：单项填空（共15小题；每小题1分，满分15分）
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。
1.Someone is ringing the doorbell. Go and see____.
A. who is he B. who he is C. who is it D. who it is
2.The manager of the company told us that very little ____was made of the waste material in the past.
A. cost B. vale C. use D. matter
