【提出问题】化学反应前后各物质的质量总和是否相等？

【查阅资料】氢氧化钠溶液可以吸收二氧化碳气体

【猜想与假设】猜想1：不相等；       猜想2：相等．

根据对话内容，选择合适的句子填空

Sam: Who are they,lingling?

Lingling: ____.

Sam: ____?

Lingling: It's my grandma.

Amy: ____.

Lingling: ____?

Amy: Did she learn any foreign languages?

Lingling: ____.

根据短文内容，判断正误。

    I have a good family. There are four people in my family. They are my father, my mother, my sister and I. My father is 40. He is a Chinese teacher. My mother is 38. She is an English teacher. They work in different schools. My sister's name is Li Fang. She is ten. We are in the same school, but in different grades. We have a nice picture of our family. It's on the wall. Look! Our father and mother are on the chair, and we two stand behind them.