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Dogs are man's good friends. Some dogs are big, and some dogs are small. Dogs are very clever, but they can't see colours. They are colour-blind. In a dog's eyes, everything is black, white and grey. How can a dog hunt (捕猎) for food then? Dogs can run very fast. They can hear (听) and smell (闻) very well, too.
Many animals can't see colours. Lions, tigers, cats, cows and sheep are all colour-blind. But monkeys can see colours. Many birds, fish and insects (昆虫) can see colours, too.
1．Dogs _______ see colours. ( )| A．can | B．can't | C．often |
| A．black, white and grey | B．black, white and green | C．black, white and brown |
| A．see colours | B．sing and dance | C．hear and smell |
| A．Tigers | B．Many birds | C．Sheep |
| A．色盲 | B．彩色的 | C．有颜色的 |
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
