When you walk in the country, you should follow these rules:
* To protect the trees, don’t start fires (点火) in the forest.
* Don’t throw rubbish here and there. When you leave, take away waste paper and bottles.
* Keep the river clean. The water here is used for drinking.
* Please protect animals and plants. Don’t shoot (射杀) birds. Don’t pick flowers.
1.We should follow the rules to protect the environment.
2.We can smoke in the forest.
3.We should leave waste paper and bottles on the ground.
4.The river water in the country is used for drinking.
5.We can pick flowers in the country.
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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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