输煤系统控制方式有哪几种？
参考答案：
输煤系统的控制方式有三种，即就地手动控制、集中手动控制、集中程序控制。
大型火电厂中，目前常用的燃煤计量设备有电子轨道衡、电子皮带称、核子称。
-Mike, it's a pity you didn't come to last night's concert. Itwas really great!
-Really? If I _____ so busy, I would have gone with you. [ ]
A. hadn't been
B. weren't
C. shouldn't be
D. wouldn't be
