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People, animals and plants live on the Earth. The Earth takes one year to go around the sun. The moon takes a month to go around the Earth. In fact, the moon and stars don’t give light. They can only reflect the light of the sun. The sun is a fire ball. It keeps burning all the time. It’s far away from the Earth. It’s much bigger than the Earth. The moon is much smaller than the Earth. But you should remember that: The Earth is our only home. We must protect(保护) her. Only the Earth has water and air.
1．The Earth takes2．
3．The Earth is
4．
5．There is water and air
同类型试题
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
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
