书城教材教辅科学读本(英文原版)(套装1-6册)
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第40章 第一册(40)

"You must try to keep in your mind the word, which teacher gave us for this. We say that we dissolve salt in water, because the salt loosens and breaks up in the water, so that we cannot see it. Teacher says to dissolve means to loosen or break up. Don"t forget that we can dissolve salt, sugar, soda, alum, and lime.

"But," added Will, "we can"t dissolve everything, Norah. We can"t dissolve stones, chalk, iron, glass, or wood."SUMMARY

When we put salt into water it breaks up into such little pieces that we cannot see them. We dissolve the salt in the water. It does not melt. We can also dissolve sugar, soda, alum, and lime in water. But we can"t dissolve stones, chalk, iron, or wood.

The Sheep

"Come into the field," said Fred, "and let us watch the sheep feeding. But you must not go too near them, for they are very timid, and will run away.