智能电网调度支持系统实时监控预警应用试点单位是（）。
A.华中
B.华东
C.华北
D.西北
参考答案：C
John invited approximately 40 guests to his wedding, most of _______ are family members.
A．whom
B．that
C．them
D．which
-3x-my2与5x3y2是同类项，则m的值是（ ）
A．-2
B．-5
C．3
D．-3
