A.1/4B.1/3C.1/2D.1/5
A.試管口應(yīng)略向下傾斜B.試管口應(yīng)略向上傾斜C.試管夾從試管底部下向上套入D.試管夾夾在離試管口1/3處
A.Na2SO4B.NaHSO4C.HClD.檢測(cè)溢出氣體的pH試紙變紅