Finish your homework first,and then you'll watch TV for an hour.
A:can
B:be able to
C:able to
D:could
如果约定街在前,巷在后,则某单位在5街2巷的十字路口,用有序数对表示为( )
生活中一些物质的pH如下图所示,其中碱性最强的是( )