抛物线y2=2px上一点M（4，m）到准线的距离为6，则p= _________ ．
4
The first thing ______ we should do is to tell him the news. [ ]
A. who
B. which
C. that
D. whom
判断某项功能是否具有战略意义，关键是看他的（）
A.替代性
B.延展性
C.系统性
D.创新性
