选项 | 类群名称 | 特征 | 实例 |
A | 爬行类 | 体表覆盖角质的鳞片或甲,表皮干燥、呈鳞片状,在陆地上产卵 | 乌龟、鳄鱼 |
B | 鱼类 | 生活在水中,用肺呼吸,无四肢,用鳍划水 | 草鱼、鳙鱼 |
C | 鸟类 | 流线型、被覆羽毛、有两翼、有气囊 | 家鸽、蝙蝠 |
D | 两栖类 | 皮肤裸露、幼体用鳃呼吸、成体用肺呼吸、体温不恒定 | 鲸、娃娃鱼 |
A.A | B.B | C.C | D.D |

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

