A:;
B:;
C:;
D:
(变大/变小/不变).
用括号内所给单词的适当形式填空(1)What a____ (please) it is for me to play the piano with you!(2)Mother asked the Greens to help____(they) to some pears.(3)Tim sings even____ (badly) than before.(4)He felt____ (true) sorry for what he said.(5)____ (clean) work is to make our city clean.
比一比再组词。
彻____ 掉____ 哀____ 炊____
砌____ 悼____ 衰____ 吹____
选项
实验目的
实验方案
A
除去稀硫酸中的FeSO4
加入适量铁粉
B
除去CO2中的CO
将气体通入NaOH 溶液
C
除去CaCl2溶液中的HCl
加过量CaCO3,过滤
D
除去NaCl中的Na2SO4
加过量BaCl2溶液,过滤