The dog has bright and knowing eyes, but he cannot see at night so well as the cat can. The pupil, or little black space in the middle of each eye, is never so large as that of the cat. Pussy chases the mice by night, but the dog hunts only in the day-time.
狗长着明亮的、善解人意的眼睛, 但晚上看东西不像猫看得那么清楚。狗的瞳孔, 也就是每只眼睛中间的小黑点儿, 始终不会像猫一样大。小猫咪可以在晚上追老鼠, 但是狗只在白天才狩猎。
There is another difference between the dog's eye and the cat's. Do you remember reading in the previous Lesson that in a bright light the pupil of the cat's eye closes until it is only a narrow slit? The pupil of the dog's eye is not like this. It is always round, however bright the light may be.
狗和猫的眼睛还有一处不同。你还记得吗? 在前面的课文中猫眼睛的瞳孔, 在强光下, 会眯得只剩一条缝。狗眼睛的瞳孔却不会这样, 不管光线怎么强烈, 瞳孔一直是圆的。
Notice the dog's teeth. How white and strong they are! All his teeth are sharp and pointed. He has seventeen teeth in the upper jaw, and nineteen in the lower jaw.
注意狗的牙。这些牙齿好白好硬啊！狗的牙齿全都是很尖很锋利的, 上腭有17颗牙齿, 下腭有19颗。
The dog has two long teeth in each jaw for seizing his prey. The other teeth are for tearing the flesh and crushing the bones on which he feeds. The dog lives chiefly on flesh, and he has no flat teeth for grinding his food, like those of grass-eating animals.
狗的上下腭各有两颗长长的牙齿, 用来咬住猎物。另外的牙齿用来把肉撕裂, 把骨头碾碎, 狗就吃这些肉和骨头为生。狗的食物主要是肉, 没有用来磨碎食物的扁平牙齿, 这一点跟食草动物不一样。
Grass-eating animals like the cow can move their jaws sideways as well as up and down, in order to grind their food well; but flesh-eating animals like the dog can only move their jaws up and down.
牛一类的食草动物, 上下腭除了上下活动, 还可以横向活动, 这样可以把食物磨得很碎；但是, 食肉动物的上下腭, 只能上下活动。
The tongue of the dog is long and smooth. It is very different from the rough tongue of the cat. When a dog is very hot, he always lets his tongue hang out of his mouth, for it is by his tongue that he sweats or perspires.
狗的舌头又长又光滑, 跟猫的粗糙的舌头很不一样。狗在非常热的时候, 总是把舌头伸到嘴外面, 因为狗是用舌头出汗或者排汗的。