注射模塑过程中,对熔体粘度大的塑料,塑化压力应取()。
A.高
B.低
参考答案:A
维持细胞外液渗透压的重要离子是()
A.K+
B.Na+
C.Mg2+
D.H+
E.Ca2+
A call between any two ship stations on an intership working frequency shall have a maximum duration of().
A.2 minutes
B.3 minutes
C.4 minutes
D.5 minutes