在0—l0中,偶数有( ),奇数有( ) ,质数有( ) ,合数有( )。
2,4,6,8,10;1,3,5,7,9;2,3,5,7;4,6,8,9,10
A huge amount of oil was spilt on the East Sea, the causes of_____ are still under investigation. [ ]
A. it
B. that
C. which
D. whom
物理层的功能包括( )。
A.实现实体间的按位传输
B.实现实体间的按帧传输
C.实现实体间的按分组传输
D.实现实体间的按报文传输