Diving or Drowning

A rich young man decided that he would like to do some diving in the sea, so he bought a rubber suit and all the other things that he needed, and took some lessons at a diving school. Then one day he walked into the water by himself and began to explore the bottom of the sea.

He saw a lot of beautiful fish and other things, and then, after half an hour, he suddenly saw a man waving his arms and legs around wildly near the bottom of the sea. He was wearing only a bathing suit.

The rich young man was very surprised to see him, so he took out a plastic notebook and a special pencil, which could write under water, and wrote, “What are you doing here?”

He showed the notebook to the other man, who then took the pencil and wrote, “Drowning!”

小题1:What did the rich young man want to do?

A．driving

B．diving

C．walking

D．swimming小题2:How did he prepare himself for this?

A．He bought all the things needed for diving.

B．He took a diving lesson

C．He bought a rubber suit and a bathing suit.

D．both a and b.小题3:What did he first see at the bottom of the ocean?

A．some fish

B．some plants

C．a man with a bathing suit

D．a man with a diving suit小题4:What was the man doing?

A．swimming

B．diving

C．searching for fish

D．drowning小题5:What did the rich young man do?

A．He talked with him.

B．He pulled the man out of water.

C．He communicated with the man by writing.

D．He gave his suit to the man.

（8分）实验室有5种白色固体，老师让化学实验小组同学鉴别这些固体。

（1）调查研究

①5种白色固体分别是：NaOH、Na₂CO₃、CuSO₄、Ca(OH)₂和NaHCO₃。

②查阅资料：小组同学查阅了NaOH、Na₂CO₃和NaHCO₃的一些性质。

实验步骤		实验现象	实验结论
第一步：在5支试管中分别放入少量的5种白色固体，分别标上A、B、C、D、E，然后依次加入一定量的水并振荡。		A、C、D的溶液为无色；B的溶液为浑浊；E的溶液呈蓝色。	B是              E是
第二步：向上述A、C、D溶液中分别滴加无色的酚酞溶液。		三支试管中的酚酞溶液均变红。	结论：
第三步： 依据右图装置，对A、B、C进行实验。
	①加热固体A	B溶液无明显现象。	A是Na2CO3
	②待①停止加热后，通过长颈漏斗向C溶液中加入稀盐酸	C溶液中有气泡产生，B溶液中有气泡逸出并有白色沉淀生成。	B溶液中发生反应的化学方程式为
第四步：依据右图装置，对B、C进行实验。		被加热的试管口有无色液滴生成，B溶液中有气泡逸出且溶液变浑浊。	C是            利用排除法得出： D是NaOH