书城教材教辅科学读本(英文原版)(套装1-6册)
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第59章 第一册(59)

What happens when the rain sinks into the ground and washes through the salt-beds down below?""Oh, I know," said Norah. "The water dissolvesthe salt and carries it away."

"Quite true," said Fred. "Now in the soil of our garden there is all that the plants want for food. But it is no use to the plant, till the rain sinks in, and dissolves it. If the plants do not get water they droop and die. They die because they are being starved. There is plenty of food for them in the soil, but the root-hairs cannot absorb it, till the water comes to dissolve it."SUMMARY

The root feeds the plant with food from the soil. The root- hairs are the real feeders. They are made up of a great many very small cells, with soft, thin walls. These cells take in food, which the rain dissolves out of the soil, and pass it upward to feed the plant.

Lesson 30

About Burning

"We are going to have a chat tonight about things that burn," said Fred.