— Mom, I need ________ some bread.
— OK. It's on the table.
A:to having
B:having
C:to have
D:has
生物种类最少的生态系统是( )
反比例函数y=3x(k为常数,k≠0)的图象位于( )
下列各组物质的溶液不用其它试剂就可鉴别的是( )