A.蚜虫的幼虫和成虫食性差别很大,这对于幼虫的成活是有利的 |
B.青蛙的幼体用鳃呼吸,决定了幼体的发育必须在水中进行 |
C.家燕能产具有坚硬外壳的卵,使胚胎在相对稳定的环境中发育 |
D.人类的胎生可使胚胎得到有效保护,哺乳利于婴儿的健康发育 |

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

