【英语时差8,16】谈谈减肥
时间：2019-03-06 作者：英语课 分类：英语时差8，16
Why does blowing on hot soup help to cool it off? It’s because of evaporation 1. Evaporation cools down a liquid because the most energetic molecules 3 leap off the surface and leave the slower-moving molecules behind. Slower-moving means lower temperature. The more a liquid evaporates, the more it loses heat. The hot soup forms a little cloud of vapor 2 above it that prevents more evaporation from taking place. The fast-moving molecules can’t escape the soup any more, because this little fog of water vapor has saturated 4 the air. It just can’t take any more vapor, but blow that cloud away and the fastest molecules can escape the soup! The more you help the fastest molecules to escape the soup, the more you help the soup to cool off.
- Be careful not to lose too much liquid by evaporation.小心不要因蒸发失去太多水分。
- Our bodies can sweat,thereby losing heat by evaporation.我们的身体能出汗，由此可以蒸发散热。
- 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。
- The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
- Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。