搜索
（_____）The air is cleaner, the clouds are whiter.
(1) I am a bird. I fly in the sky. I like clouds. They are pretty. I live in a tree. The tree is near a river.
（_____） There aren’t any fish in the river. There is only one tree. I feel lonely.
（_____） Then there are more and more trees and flowers. There are many fish in the river.
(4) They grow flowers, too.
（_____） More birds come. I am happy.
（_____） One day, I see some students. They are planting trees.
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
