如何区分腐蚀等级?
参考答案:
中国石化将石油化工系统的腐蚀分成四个等级单位:mm/a
耐蚀性比较
1、0.1完全耐蚀
2、0.1-0.5较耐蚀
3、0.5-1.0尚耐蚀
4、1不耐蚀
Not much people realize that apples have been cultivated for over 3, 000 years.
A.Not many
B.Not enough
C.Without many
D.No many
低温贮存较久的血液,血浆中哪种离子浓度升高
A.Na+B.K+C.Cl-D.Ca2+