煤气管道的（）设备，一般是指：阀门、补偿器、排水器、放散管、人孔、支架等。
A.附属
B.主体
C.电气
D.制冷
参考答案：A
When you rewrite the paragraph, I advise you to leave out ________ is thought unnecessary or
misleading. [ ]
A. what
B. that
C. these
D. which
请简述病毒的特点
or