Good luck and hope _____ you again sometime soon.
A:sees
B:seeing
C:see
D:to see
下列选项中,各组内物质之间不能发生反应的是( )
如果﹣4xaya+1与mx5yb﹣1的和是3x5yn,求(m﹣n)(2a﹣b)的值.