美国小学英语教材5:第64课 小小美国伐木工(2)
时间：2019-02-19 作者：英语课 分类：美国小学英语教材5
英语课
These trees he fells toward each other, so that, if possible, their tops meet. 他让这些树彼此靠近，这样，如果可能的话，树的顶部就会相接。
When this is done, he has the backbone 1 for his dam. 当这一切完成后，他就有了建造水坝的支柱。
Then he fills in with stakes and small logs and finally plasters up all the holes with mud and sod. 然后他用树桩和小圆木填充，最后用泥和草皮把所有的洞都填满。
When he has finished, it is as tight as any man-made dam. 当完工时，就像任何人造水坝一样坚固。
But if trees are not available, he can do without them; he can cut logs, roll them into place, and make a dam wholly out of logs. 但如果没有树，他也可以照样建造；他可以砍伐原木，把它们滚到合适的地方，然后完全用原木筑坝。
The beaver 2 seems to understand how powerful moving water is. 海狸似乎明白流动的水的力量。
At any rate, his dam usually curves upstream in the middle, and every engineer knows that a dam built in this way is the strongest. 无论如何，他的水坝通常在中间向上游弯曲，每个工程师都知道以这种方式建造的水坝是最坚固的。
The beaver also provides a waste waterway which runs around one end of the dam. 海狸还做出了一条环绕水坝一端的废弃水道。
So, when the water is high, it flows around the end instead of washing away the top of the dam. 所以当水位很高的时候，水会绕着水坝的末端流动，而不是冲走水坝的顶部。
He is very watchful 3 of the dam, and if it begins to leak, he investigates at once. 海狸非常小心，如果水坝开始漏水，就立即进行调查。
n.脊骨，脊柱，骨干；刚毅，骨气
- The Chinese people have backbone.中国人民有骨气。
- The backbone is an articulate structure.脊椎骨是一种关节相连的结构。
n.海狸，河狸
- The hat is made of beaver.这顶帽子是海狸毛皮制的。
- A beaver is an animals with big front teeth.海狸是一种长着大门牙的动物。
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美国小学
