人的体温正常有赖于()
A.气的推动作用
B.气的温煦作用
C.气的防御作用
D.气的固摄作用
E.气的气化作用
参考答案:B
When he was a child, he was always ______ out new ideas. [ ]
A. try
B. trying
C. taking
D. tried
网络子系统(NSS)一般包含哪几个部分?