中国药典(2000年版)古蔡氏检砷法中,使用醋酸铅棉花的目的是
A.除去硫化氢气体B.除去砷化氢气体C.除去锑化氢气体D.除去二氧化碳气体E.除去三氧化硫气体
参考答案:A
______ people visit Beijing zoo every day. [ ]
A. Sixteen thousand
B. Sixteen thousands
C. Sixteen thousand of
D. Sixteen thousands of