纯水中存在电离平衡:H2OH++OH-欲使该平衡向正方向移动,且c(H+)增大,应加入的物质是 [ ]
A.NaHSO4
B.AlCl3
C.NaHCO3
D.NaOH
答案:B
使徒信经
水平井固井要求水泥浆自由水和水泥石上下密度差分别小于()。
A.5%,0.06kg/L
B.0.5%,0.06kg/L
C.0.5%,0.6kg/L