列管换热器()过程中涉及导热、对流两种传热方式和热辐射传热。
A.压强
B.传热
C.流量差
D.压差
参考答案:B
225的3倍是多少?
In copying this paper, be careful not to leave _______ any words.
A.aside
B.for
C.out
D.off