英文科學(xué)讀本 第一冊(cè)·Lesson 02 Water—A Liquid

Lesson 02 Water—A Liquid

Norah's mother called her away to mind the baby, before the boys had told her all about their lesson.

She came back as soon as she could, and they began to chat again.

I wonder whether Norah forgets what we learned about water, said Fred.

No, said Norah, "I don't forget. I know that water flows, and it always flows down. It keeps a flat surface, and it cannot stand in a heap. It breaks up into round drops, but the drops will run together again, and make a pool of water."

Quite right, said Fred. "But now I'm going to puzzle you. Can you tell me what shape water is?

Teacher tried to puzzle us; didn't he, Will? But he soon made it clear. He showed us the saucer, and we saw that it was round. Then he filled it with water, and of course it was easy to see that the water in the saucer was round too.

But the water did not remain round, said Willie, "for teacher next poured it out of the saucer into a square tin box."

I know. said Norah, "it became square then, like the box."

Right, replied Fred, "and then we saw the water poured out of the box into a tumbler; out of the tumbler into a jug; out of the jug into a bottle. It took the shape of the new vessel each time.

Can you think of any other things, Norah, that would do as water does?

I know some, said Norah. "Milk and oil, vinegar and tea would do the same."

Now, Norah, said both boys at once, "you must try not to forget the proper name for all these things. Teacher tells us to call them liquids.

Liquids flow about, break up into drops, take the shape of the vessel which holds them, and cannot stand in a heap, but always keep a level surface.

SUMMARY

Water has no shape of its own. It always takes the shape of the vessel which holds it. Water, milk, oil, and vinegar are liquids.