下列选项不是网络渠道的特点是（）。
A.随时性和及时性
B.数字化
C.全球性
D.便捷性
参考答案：D
-8的相反数是 .
In the old days, people ______ a fire with wood in our village.
A．were used to make
B．used to making
C．used to make
D．used making
