溶液 | 清水 | 1%酒精 | 10%酒精 | 20%酒精 |
每10秒的心跳次数 | 42 | 36 | 18 | 死亡 |
A.该实验设置清水组是为了做对照实验 | B.实验水蚤可随意选择体型大小不同的 |
C.同一只水蚤应先在酒精溶液中,后在清水中观察心率 | D.高浓度的酒精对水蚤的心率有促进作用 |
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