回族一般实行内婚制，本族姑娘不外嫁，男性可娶外族姑娘。（）
参考答案：对
— Could you play the guitar when you were 8 years old?
— _____. [ ]
A. Yes, I could.
B. No, I can't.
C. Yes, I can.
D. No, I won't.
下列燃烧反应的反应热是燃烧热的是( )
A．H2(g)＋O2(g)===H2O(g) ΔH1
B．C(s)＋O2(g)===CO(g) ΔH2
C．S(s)＋O2(g)===SO2(g) ΔH3
D．H2S(g)＋O2(g)===S(s)＋H2O(l) ΔH4
