“三大改造”指的是我国对下列哪些行业的社会主义改造（  ）

①农业    ② 手工业  ③资本主义工商业  ④交通运输业

根据短文内容，用方框中所给单词的适当形式填空，并将答案写在相应的横线上。每词限用一次。

    Lisa and Alice are good ____. They go to a children's hospital today. They want to help the children to be happy. Lisa ____ reading. So she tells ____ to them. Alice likes singing and ____. She sings some English songs for the children. They go home late, but they are very ____.

测定BaCl₂·xH₂O中结晶水数目的过程如图所示：