A.4:1
B.1:
C.2:1
D.:1
答案:C
The chances of a repetition of those unfortunate events are ______ in deed.
A.distant
B.slim
C.unlikely
D.narrow
通信服务的特点()
A.无形性
B.差异性
C.可分离性
D.不可存储性
E.无所有权转移