若﹣7xm+4y2与﹣3x3yn﹣2是同类项,则mn=( )
1
I think it is a top priority for the government to furnish the children with ___to the information superhighway.
A.procedure
B.allowance
C.means
D.access
导爆索中药芯的成分是()。
A.黑索金
B.炸药
C.黑火药
D.TNT