(4分)请完成下列各空:(1) pH= a的CH3COOH溶液稀释100倍后所得溶液pH a +2(填“>”或“<”下同)(2)0.1 mol·L-1CH3COONa溶液的pH 7 答案:(4分)(1) < (2) > 解析:
-When did you get your first pair of skates?
-________.
[ ]
A.For 6 years
B.Since I was 7 years old.
C.When I was 7 years old.
D.Since 6 years ago.