方程x（x+1）=0的解是______．
x（x+1）=0
x=0或x+1=0
x1=0，x2=-1
故本题的答案是x1=0，x2=-1
目前用于烤瓷的合金中不包括（）
A.金合金
B.钛医学合金
C.镍铬合金
D.纯钛金属
E.半贵金属
Daddy didn't mind what we were doing, as long as we were together, ______ fun. [ ]
A. had
B. have
C. to have
D. having
