书城教材教辅科学读本(英文原版)(套装1-6册)
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第140章 第二册(57)

"Right again. Cast-iron is not ductile, and cannot be made into wire."SUMMARY

Cast-iron melts with less heat than other iron. It is poured, in the liquid state, into molds, and takes their exact shape. Cast- iron is very brittle. It is neither malleable nor ductile.

Lesson 26

Milk, Butter, Cheese

"While we were talking about the cow the other day," said Norah, "we forgot all about the milk she gives us. Milk forms part of our daily food. We drink it; we put it in our tea, coffee, and cocoa; we use it for making puddings with sago, corn-flour, rice, and tapioca.

"I"ve been thinking that as these starch foods cannot make flesh, perhaps we put milk with them, because the milk can make flesh. Is that so, Fred?""

"Wait," said Fred, "and I"ll show you that you are quite right, Norah.

"Did you ever see some milk that had been left to stand for a time?""Oh yes," said Norah. "There is always a thickcream floating on the top."