A.添加液体时,倒入的液体过多,可将多余的液体倒回原试剂瓶 |
B.实验中不慎打翻酒精灯,可用湿抹布盖灭 |
C.制作过滤器时,若过滤器的角度与漏斗的角度不吻合,可改变第二次对折的角度 |
D.用高锰酸钾制取氧气并用排水法收集后出现倒吸现象,可立即松开试管上的橡皮塞 |

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

