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. I wonder if I should ________ his smile as an acceptance or a refusal.
A. receive B. believe C. interpret D. suppose
22. Lily gave us a vivid _________ of her trip to Mount Tai after her return.
A. explanation B. account C. opinion D. comment
