书城教材教辅科学读本(英文原版)(套装1-6册)
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第48章 第一册(48)

"Why, it soaks into the earth," said Norah, "because the earth is porous, and absorbs it.""We are making our little girl very clever," said Fred, "but she is quite right. Isn"t it jolly, Will, to have a fine teacher? We couldn"t tell Norah all these things, if he did not take a lot of trouble to make it easy for us.""That"s what I say," said Willie.

"Now tell us, Norah," said Fred, "suppose some of this water, as it soak down into the earth, comes to one of these beds of rock-salt. What would it do to the salt?""Why, I suppose it would dissolve the rock-salt, and make brine," said his sister.

"You are right," said Fred. "That is just what it does. Teacher says when men want to get this brine, they bore a hole through the ground, till they come to the bed of salt. Then they put a long pipe down the hole. The brine runs into the pipe, and then they pump it up.""I think I can tell you the rest," said Norah, who was busy thinking. "They boil the brine, and the salt is left behind.""Yes, they do," said Fred. "They boil it in great pans as big as this room. And that is how we get salt for the table."SUMMARY