1. We should plant more trees to keep the air clean. (改为一般疑问句)
______ ______ plant more trees to keep the air clean?
2. You should turn off the lights to save energy. (改为一般疑问句)
______ ______ turn off the lights to save energy?
3. You should cut more trees.(改为否定句)
You ______ ______ ______ more trees.
4. We should use many plastic bags and plastic bottles.(改为否定句)
We ______ ______ use many plastic bags and plastic bottles.
5. We should save and reuse water.(改为疑问句)
______ ______ save and reuse water.

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

