A.镁条在空气中燃烧,冒出浓烈的黑烟,放出热量,生成黑色粉末 |
B.铁丝在氧气中剧烈燃烧,火星四射,放出热量,生成红色粉末 |
C.向滴有紫色石蕊的水中通入二氧化碳,再加热,颜色变化为:紫色→红色→紫色 |
D.红磷在氧气中燃烧时,产生大量白色烟雾。 |

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

