根据材料内容,选择正确答案。
Here is a dog with a lantern(提灯) in his mouth. He is looking for his master(主人).
Carlo, a lovely dog, had been taught to be useful. The roads, in the place where his master lived, were often so bad that it was not safe for any person to go out without a light on dark nights.
So Carlo's master taught him to carry a lantern for him at night, and he did it as steadily(稳固地) as any boy could have done.
Carlo never trotted(小跑) too far before his master so that the bright light of the lantern might guide his master's steps.
When he came to a deep rut(车辙) or hole in the road, he would turn round to his master, seemed to say, “Take care, there is a hole here.''
The dog's master lived about a mile from the town, and when he could not get home before dark, Carlo used to be sent to him with the lantern. Carlo usually knew where to go. He also knew the road which his master would take.
But Carlo didn't always find his master right away. When he reached the town, he would run off to a house where his master often was. Still holding his lantern, he would scratch at the street-door with his feet and bark(吠叫), as much as to say, “Here am I, Master, with the lantern, are you ready for home?''
Someone would perhaps come to the door and say, “Your master is not here.” Carlo would growl(嘟哝), seemed to say, “Then he is somewhere else, and I must find him.”
He would then run off to one house after another, until he found his master, and then the two went home together.
