Look! All people _______ fun at the beach.
A:has
B:having
C:have
D:are having
函数f(x)=x2﹣2ax+a在区间(﹣∞,1)上有最小值,则a的取值范围是( )
分式xy2x+3y中的x,y都扩大5倍,则该分式的值 ( )