Lesson 91 Milk And Its Uses 第91课 牛奶及用途 Every child likes to drink new milk. 每个孩子都喜欢喝鲜牛奶。 How pleasant it smells and how sweet it tastes! 那香浓的味道, 甜美的滋味是多么诱人！ Do you not want to kn...
and hang it point downwards from a strip of wood placed across the top of a wide-mouthed bottle, or a pickle-glass, or a tumbler, half full of water. 然后尖头朝下悬挂在一片横放在装有半瓶水的宽口瓶、泡菜瓶或平底玻璃杯口...
If we take the acorn out of its cup and soak it in warm water for a few hours, it will split open, 如果我们把橡子从中取出, 放入温水浸泡, 几个小时之后它就会裂开。 and we shall see that it consists of two thick seed-leaves,...
Lesson 90 The Sturdy Oak 第90课 结实的橡树 The oak is one of the finest and most useful of all our forest trees. 在所有森林树种之中, 橡树是最为优良、最为有用的一种树木。 Its height sometimes exceeds sixty feet, while...
Every day the sun's rays change thousands of tons of liquid water into water-vapour; 每天, 太阳光都能够将数千吨的液态水转化为水蒸气； and this water-vapour mingles with the air, and is carried along by the wind. 随后, 水蒸气...
Lesson 89 Clouds And Rain 第89课 云和雨 Each of us drinks about three pints of fresh water every day, and we use a great deal of water for washing, for cooking, and for other purposes. 我们每个人每一天都会饮用3品脱左右的淡水, 而...
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...
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...
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...
These bristles point backwards. 这些刚毛朝向后方。 If we move a finger along the worm from the head to the tail, the body feels quite smooth; 用一根手指从蚯蚓的头部摸向其尾部, 就会感觉它的身体非常光滑； but if we...
