锅炉三冲量给水自动调节系统中,三冲量是指汽包水位,()。
A.蒸汽流量,给水流量
B.给水流量,给水压力
C.给水压力,汽包压力
D.汽包压力,给水压力
参考答案:A
请根据下面提示,写一篇短文。词数不少于50。
In your English class, you are asked to describe the following picture and explain to your classmates how you understand it.
在水田中立杆时,在电杆底下应加(),在地质松软地带的角杆,还应装设(),否则吊线垂度难以保证。