单词：water vapour permeability tester for leather
单词：water vapour permeability tester for leather 相关文章
When we change a liquid into vapour, and cool this vapour till it is liquid again, 将水加热成水蒸气, 然后对其进行冷却直至再次液化, we are said to distil the liquid, and the apparatus for doing this is called a still. 这个过程就
英国学生科学读本
Thus by heating liquids we cause them to evaporate, or change into vapours or gases; 因此, 可以看出：我们能够通过加热液体使得它们蒸发, 变成水蒸气或气体； and by taking away heat from these gases, or cooling them, we tu
英国学生科学读本
Lesson 88 Condensation 第88课 冷凝 When the water in a kettle boils, it boils first at the bottom. 当水壶中的水沸腾时, 首先开始沸腾的是底部的水。 We cannot see this in a kettle, because the kettle is made of iron. 我们无法
英国学生科学读本
Lesson 70 Evaporation 第70课 蒸发作用 Let us fill a small kettle with water, and place it on the fire. The water will soon begin to boil. After an hour or so we shall find the kettle quite empty, although no one has touched it since it was plac
英国学生科学读本
The finger which is wet with alcohol will be dry before you can count ten, while the finger which is wet with water may take a minute or more to dry. 在你数到十之前, 那根沾有酒精的手指就会变得干燥, 而另外一根沾有水的手指
英国学生科学读本
Lesson 35 Getting up Steam 第35课 蒸汽往上冒！ Do you want to know what steam is? Let us get a lump of ice, or a snow-ball, and place it in a saucer in a warm room. It soon melts, and then the saucer is half full of water. If we leave the sau
英国学生科学读本