A.早春播种后用地膜覆盖,是为了保持温度和湿度,有利于种子提早萌发 |
B.移栽泡泡青幼苗时,根部带有土团的目的是防止幼根和根毛受损 |
C.泡泡青生长期要水肥充足,施肥的作用是给植物的生长提供有机物 |
D.选择阴天或傍晚移栽幼苗,可使蒸腾作用减弱,减少水分散失 |

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

