16．－Governments at all levels have to take measures to improve the quality of basic education.

－Exactly. _________, students' homework must be greatly reduced.

A．That's to say

B．What's more

C．Believe it or not

D．In a word

有三瓶无色透明的液体，分别是碳酸钠溶液、氢氧化钠溶液和氯化钠溶液，请设计一个实验方案把这三瓶液体区分开来，并将实验操作、预期现象和结论填写在下表中．