根据短文内容，选择方框中恰当的句子填入空白处，使补全后的短文意思通顺。（5分）

I’m Sam Red. There are seven people in my family. They are my parents, my two sisters, my brother, his wife(妻子) and I. In England, a family like this is a big one. My father has a farm. It is very big. My brother is a doctor. ____小题1:____. His wife works in a hospital, too. ____小题2:____. My two sisters are students. Helen wants to be an English teacher. ____小题3:_. Julia likes to sing very much. She can sing very well. So she wants to be a singer(歌手). I’m in China now. ____小题4:____ My mother doesn’t go to work. What does she do at home? ___小题5:___ Oh, she does housework(家务). She is a housewife.

（6分）材料是科学进步的关键，不同的化学物质有不同的用途。现有①氯气、②氨气、③单质硅、④水玻璃四种物质。其中可以用作制冷剂的是              ；常用作木材防火剂材料的是           ；可以用来消毒杀菌的是              。（填序号）