A.向某固体中滴加稀盐酸,有气泡产生,则该固体一定是碳酸盐 |
B.向某无色溶液中通入CO2,无明显现象,则该溶液一定不与CO2反应 |
C.向某无色气体中伸入燃着的木条,木条熄灭,则该气体一定是CO2 |
D.向某无色溶液中滴加无色酚酞试液,溶液变红,则该溶液的pH一定大于7 |
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