____ to travel by boat on a hot summer night!
A. So pleasant
B. How pleasant it is!
C. Such a pleasant
D. How pleasant is it
查看答案
____ good time they are having at the party now!
A. What
B. What a
C. How
D. How a
______ progress you have made!
A. What great
B. What a great
C. How great
D. How great a
用EDTA标准溶液滴定下列离子时,能采用直接滴定方式的是
A. SO42-
B. Al3+
C. K+
D. Ca2+
用EDTA标准溶液测定Ca2+时,消除Mg2+干扰的最简便的方法是
A. 控制酸度法
B. 配位掩蔽法
C. 氧化还原掩蔽法
D. 沉淀掩蔽法