
1.关于元阳山区立体农业系统的叙述,正确的是
A.山上河谷养种鱼,便于捕捞 | B.村寨秧田育鱼苗,便于鱼苗出售 |
C.山腰梯田种水稻,适宜机械化耕作 | D.稻田蓄水养成鱼,可以获得更多饵料 |
A.专业化程度高,利于安排农事活动 | B.资源循环利用,体现持续性原则 |
C.杜绝农药使用,农产品绿色无污染 | D.商品率高,受市场影响显著 |

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

