题干
---You don’t look quite yourself today. What’s the matter?
---Well, I’ve caught a cold. Nothing serious, ________.
---Well, I’ve caught a cold. Nothing serious, ________.
A：although
B：though
C：indeed
D：instead
答案(点此获取答案解析）
B
，那么它的一个底角的余弦值为（ 
）