已知最小相位系统的开环对数幅频特性曲线的渐近线如下图所示，试确定其开环增益K（）
A、0
B、5
C、10
D、12
参考答案：C
—What's the time, please?
—______ seven thirty. [ ]
A. That's
B. Is
C. It's
D. This's
The little girl often has nothing for breakfast, ________she?
-_______. Because she often gets up late and is afraid of being late for school.
A．has; Yes
B．doesn't; No
C．does; No
D．hasn't; Yes
