1.有关河曲地段水流速度、外力作用的组合,正确的是( )
A.甲—流速慢—沉积作用 | B.甲—流速快—侵蚀作用 |
C.乙—流速慢—侵蚀作用 | D.乙—流速快—沉积作用 |
①甲—建设防洪堤 ②甲—大规模建设住宅 ③乙—适宜建设港口 ④乙—可以建设采沙场
A.①② | B.②③ | C.③④ | D.①④ |
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