A.春分日全球昼夜平分,则全球昼夜平分一定是春分日 |
B.家庭电路中发生短路时保险丝会熔断,则保险丝熔断一定是发生了短路 |
C.单质是由同种元素组成的纯净物,则由同种元素组成的纯净物一定是单质 |
D.显微镜使用中转动反光镜可使视野变亮,则视野变亮一定是转动了反光镜 |

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

