Nat lived in a small town in England. He always stayed in England for his vacation, but last year he thought, “I’m never outside this country. All my friends go to Spain , and they like it very much. So this year I’m going there, too.”
First he went to Madrid (马德里) and stayed in a small hotel for a few days. On the first morning he went out for a walk. In England people drive on the left, but in Spain they drive on the right. Nat forgot about this and when he was crossing a busy street, a bike knocked (撞) him down.
Nat lay (躺) on the ground for a few seconds and then he sat up and said,
“Where am I ?”
An old man was selling maps at the side of the street, and he at once came
to Nat and said, “Map of the city, sir ?”

常用液体温度计是利用液体　____ 　的性质制成的．如图所示，是小亮同学在做“观察水的沸腾”实验时的装置，如果想要节约一些酒精灯的燃料，并适当缩短实验时间，则可行的一种方法是　____ 　．当烧瓶内的水沸腾后把酒精灯移开，水将不再沸腾．请你写出两种使瓶内的水再沸腾起来的方法．（用酒精灯加热除外）①　____ 　；②　____ 　．