书城教材教辅科学读本(英文原版)(套装1-6册)
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第274章 第三册(99)

"Every time the fish takes in water through itsmouth, and pours it over the gills, the blood in thelittle vessels sucks up as much of the air as it can get from the water.

"This is the creature"s way of breathing."SUMMARY

The ?sh breathes by means of gills. The gills are placed just behind the jaws. They look red, because of the blood which is ?owing through them. The ?sh takes in water at its mouth, and passes it over the gills. The water contains air in its pores. The gills suck this air out of the water.

Lesson 34

More about Coal-Gas

"Teacher made some coal-gas for us at school to- day, Norah," said Willie, "and it brought to my mind one of our very early lessons. Do you remember that we once made some gas in one of father"s long clay pipes?""Yes, of course I do," said Norah, "and when you put a match to the stem of the pipe the gas burned there as it came out.""Teacher made some gas in this way, only ever so much better than we could do it. Suppose we tell you all about it," said Will.