直线y=ax+b与x轴的交点为(-2,0),则方程ax=-b的解是( )。
x=-2
There is no doubt _________ the world climate has been changing in recent years.
A.that
B.what
C.if
D.whether
肾功能不全时,必须酌情减量的药物有()
A.四环素
B.磺胺嘧啶
C.庆大霉素
D.乙胺丁醇
E.对氨基水样酸