A.铁丝在氧气中剧烈燃烧,火星四射,放出大量的热,生成四氧化三铁 |
B.在木炭还原氧化铜的实验中,试管中的现象是固体由黑色变为红色 |
C.用砂纸打磨过的镁条放入稀盐酸中,镁条表面有气泡产生 |
D.二氧化碳通入紫色石蕊溶液中,石蕊溶液由紫色变为红色 |
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