如果m为有理数,且-m>m,那么m为[ ]
A.0到1之间的数
B.-1到0之间的数
C.所有负数
D.小于-1的负数
答案:C
This kind of social phenomenon could exist only for a few months, but it will disappear _____. [ ]
A. in no time
B. on the time
C. at a time
D. at one time
下列()产品体现直接的网络外部性。
A.电话
B.传真机
C.在线服务
D.Email