
(1)通过观察发现靠近蚯蚓身体前端的几个体节,颜色浅而光滑,称为
(2)在实验过程中,用手指来回触摸蚯蚓身体的腹面,不光滑;用放大镜观察,会看到许多小突起,这是
(3)在观察的过程中,应经常用浸水的湿棉球轻擦蚯蚓的体表,使它的体表保持湿润,目的是保证蚯蚓正常

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

