涡轮流量变送器压力降为10KPa,介质在最高温度下的蒸气压为50kPa,用回压阀调节回压压力()。
A、82.5KPa
B、60KPa
C、70KPa
D、100KPa
参考答案:A
_____ of the land in that district ______ covered with trees and grass.
A.Two-five ; is
B.Two-fifth ; are
C.Two-fifths ; is
D.Two-fifths ; are
《动物防疫法》中的动物疫病是什么?