书城教材教辅科学读本(英文原版)(套装1-6册)
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第177章 第三册(2)

"Suppose you tell us why you call water a liquid." "Oh, that"s easy," said Norah. "First of all waterhas no shape of its own. It always takes the shape of the vessel which holds it. Then, too, it cannot stand in a heap, but always keeps a level surface.

"We cannot grasp water in our hands, to pick up a handful of it, as we could a handful of sugar or flour or raisins. The water would fall away in drops out of our hands and run along the floor, because water always flows down and tries to get lower. Everything that is like water in these respects is a liquid.""I think she knows why water is called a liquid, Fred, so we may as well talk now about the other properties of water." said Will.

Fred had got several tumblers, just as he had seen his teacher do in class. He put clear water in one, and milk in another, and in the rest of them some water that he had colored with a few drops of red, black, and blue ink. He showed Norah these colored waters first, then the milk, and lastly the glass of clear water.

"Now, little girl," said he, "what color is water? You see it is not white; the milk is white. Neither is it black, or red, or blue.""I don"t think it has any color." said Norah.