阅读理解。 One day I got a duck from a friend who lived two miles south of my house. I brought the duck home in a bag. It was obvious that the duck missed his family very much upon his arrival. Left to himself, he would at once turn his head homeward. I tried to shut him together with other ducks for several days, but with no use at all. There seemed to be but one thought in the mind of him, and that was home. So I decided to let him out, but I kept about fifty yards behind him. I followed, thinking he would soon lose his way and came back. But he seemed to have an exact map of the country in his mind. Soon he met a dog. He paused and looked at the animal for a moment, and then turned to the right along a road which led to a railroad station. He had now gone about half the distance, and was getting tired. A little pool of water by the roadside caught his eye. Into it he bathed, drank, and rested for a few moments, and then started homeward again. For a while, he realized that he had got into the wrong direction, and turned his face southward again. Finally we came in sight of the home path, which led up to the farmhouse. It was now nearly night and I had no time to watch the experiment further. But as he neared the path he seemed suddenly to see some familiar things, and rushed at the top of his speed. I followed close behind. Into the house yard he rushed with uplifted wings as if he was eagerly telling his partners the story of his adventures. 1. What does the author think about the duck? [     ] A. Interesting and careful. B. Curious and enthusiastic. C. Intelligent and determined. D. Brave and experienced. 2. As soon as the duck arrived at a new place, he seemed _____. [     ] A. glad B. nervous C. tired D. homesick 3. The underlined part “the experiment” in the last paragraph refers to '_____'. [     ] A. if the duck had the ability to get on well with other ducks. B. if the duck was born with a good sense of direction. C. if the duck could discover the author. D. if the duck could find his way home. 4. What's the purpose of the writer's writing the text? [     ] A. To share us a duck's interesting trip. B. To present his opinions about a duck's remarkable experience. C. To express his curiosity about a duck's interesting trip. D. To examine why a duck would like to rush on it's own.