
A.甲图的昆虫发育的起点是受精卵,该昆虫是完全变态发育 |
B.乙为受精鸡卵结构图,为a发育提供主要营养物质的结构是d |
C.图丙中表示胎儿代谢废物排入母体血液的途径应为:③→②→① |
D.嫁接可提高水果品质。现有好吃但抗病虫力弱的鸭梨和不好吃抗病虫力强的山梨,应该将山梨作为接穗来嫁接 |

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

