⒈已知集合A=｛0,2,3｝,B=｛x|x=a·b,a,b∈A｝,则B的子集个数（）.A.4个 B.8个 C.15个 D

⒈已知集合A=｛0,2,3｝,B=｛x|x=a·b,a,b∈A｝,则B的子集个数（）.A.4个 B.8个 C.15个 D.16个
⒉设a,b∈R,集合｛1,a+b,a｝={0,b/a,b},则b-a=（）.
A.1 B.-1 C.2 D.-2