【英语时差8,16】烧水什么时候才算开？（上）

Put cold tap water in a saucepan and heat it on the stove. After a few minutes you hear a loud roar coming from the pan. The roar does not mean the water is boiling. Look at the pan and you see bubbles apparently¹ stuck to the bottom. Some of those bubbles are round and steady–they contain oxygen formerly² dissolved in the water. The oxygen is coming out of solution because hot water cannot hold as much dissolved oxygen as cold water. Other bubbles on the bottom of the pan appear to vibrate. These bubbles contain not oxygen but water vapor³, created from the liquid water by heating from below. As the first vapor bubbles break free from the hot bottom and rise into slightly cooler water a fraction of an inch above, the vapor in each bubble suddenly condenses. The vapor bubble collapses⁴ with a loud click.

1 apparently   

adv.显然地；表面上，似乎

参考例句：

• An apparently blind alley leads suddenly into an open space.山穷水尽，豁然开朗。
• He was apparently much surprised at the news.他对那个消息显然感到十分惊异。

2 formerly   

adv.从前，以前

参考例句：

• We now enjoy these comforts of which formerly we had only heard.我们现在享受到了过去只是听说过的那些舒适条件。
• This boat was formerly used on the rivers of China.这船从前航行在中国内河里。

3 vapor   

n.蒸汽，雾气

参考例句：

• The cold wind condenses vapor into rain.冷风使水蒸气凝结成雨。
• This new machine sometimes transpires a lot of hot vapor.这部机器有时排出大量的热气。

4 collapses   

折叠( collapse的第三人称单数 )； 倒塌； 崩溃； （尤指工作劳累后）坐下

参考例句：

• This bridge table collapses. 这张桥牌桌子能折叠。
• Once Russia collapses, the last chance to stop Hitler will be gone. 一旦俄国垮台，抑止希特勒的最后机会就没有了。