Some factories will do harm to our human beings’ life and the environment. They will pollute the air, and some will pollute the water. That is why we cannot see any fish in many rivers in the city. Some rivers have black colour and pungent (刺鼻的) smell. And usually the air around rivers is not so clean. What’s more, the polluted water will make people and animals sick. So the environment is very important to us. We should try our best to protect it.
1.Some factories will do harm to us. (2.Factories can only pollute the air. They cannot pollute the water. (
3.We can see many fish in rivers in big cities now. (
4.The polluted water will make people sick. (
5.Protecting the environment is very important to us. (
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同类型试题
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y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2
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y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2
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