1.How often do
2.What sport
3.题目错了吧?
答案应该是:There are many people here.
4.Though I'm very busy,I exercise in my free time.
或:I exercise in my free time though I'm very busy.
5.I'll come to see you if I have time tomorrow.
或:If I have time tomorrow,I'll come to see you.
6.for us/you/them(?) to eat