根据题意得：a-2=0，b+3=0
解得：a=2，b=-3．
则ba=（-3）2=9．
故答案是：9．
I don't know _____. [ ]
A. how is he
B. where is he
C. who he is
D. why does he come here
冷球蛋白阳性不见于（）
A.骨髓瘤
B.慢淋
C.类风湿关节炎
D.子宫肌瘤
E.恶性肿瘤
