流程经济性原则中流程的种类主要有：工艺流程、（）等。
参考答案：作业流程
____ a little earlier this morning! I missed the bus by only a minute and waited half an hour for another. [ ]
A. If I had got up
B. If I got up
C. If only I had got up
D. If only I got up
什么是物理信道，GSM的物理信道是指什么？
