答案详解：

15. M: The doctor said if I kepting smoking, I would increase my chances of having a heart attack.
W: Did he suggest reducing weight, too?
Q: What does the woman think the man should also do?
答案：A。解析：从女士的反问：“他还建议你减肥吗？”可以得出女士认为他应该减减肥。故选A。B是医生的建议而非女士。

16. M: The deadline for the sociology and computer courses is the day after tomorrow.
M: But I haven't decided which courses to take yet.
Q: What are the man and the woman talking about?
答案：A。解析：根据"Which courses to take 选什么课程"，可以知道他们在讨论选课的问题。答案为A。