Fred is a bus driver. He always drives the number 14 bus. Fred's bus goes 1the shopping mall on High Street to the park on Queen Street, then 2to the shopping mall. Fred3work at six o' clock every morning.4 bus leaves the shopping mall at ten past six. Fred is sometimes5 to work. When he is early, he sits in his bus and6the newspaper until it's time to go. Fred always stops for 7on the bus because he has to finish work at three o'clock in the afternoon. He doesn't go home by bus. He 8 ! He thinks it's really good for his health. Fred loved his 9 because he can meet different people every day. And he is very10. So the people who travel on Fred's bus like Fred very much.

通过化学实验，可以体验探究的过程，也可以从事实中得出结论或规律．分别设计简单的实验，完成下表内容，达到实验目的．