如图为实验室加热高锰酸钾制取氧气的装置。在实验过程中，当观察到气泡在导气管口连续、均匀地冒出时，才开始收集气体，其目的是

按要求填空。

“柱”字用音序查字法先查音序____，再查音节____。按部首查字法先查____部，再查____画。能组成词语____。

高温煅烧贝壳（主要成分是碳酸钙）可以生成氧化钙和二氧化碳，现有10t贝壳煅烧后质量减少了2.2t，可制得氧化钙的质量是多少？（假设其它成分不参加反应）

根据短文理解, 从A、B、C、D四个选项中选择正确答案填空。

    Mr. Smith 1 from London. Now he is in China. He is 2. He teaches 3 a middle school. He works very hard. His students like 4 very much. He can 5 a little Chinese. His students often teaches him Chinese 6 Sundays. Mr. Smith likes playing football. He often plays football 7 his students.

    Mr. Smith 8 a son. His name is Jack. He is student. He studies in a middle school. He goes to school 9 bike everyday. He gets back home at four in the afternoon. He likes 10 TV in the evening.