You can't imagine ________ difficult the road to success is.
A:what
B:how
C:what a
D:what an
下列各项中,没有语病的一项是( )
已知圆O的直径是方程x2﹣5x﹣24=0的根,且点A到圆心O的距离为6,则点A在( )
We don't go to school _________.
下列各式计算正确的是( )