In this task, you're given an article, a question which often contains a blank and four options (associated with "A", "B", "C", "D"). Your task is to find the correct answer (from the given options) for the question from the given article and return one of the options from "A", "B", "C", and "D". Do not generate anything else apart from one of the following characters: "A", "B", "C", "D". There is only one correct answer for each question.

[Q]: Article: The Chinese invented paper in 105 A. D. They mixed the bark of a tree and rags with water, put a screen into the mixture, and lifted out a thin piece of wet paper. They dried the paper in the sun. The Chinese kept their secret of how to make paper until a war with Muslims in the ninth century. The art of papermaking soon spread throughout the Muslim world. The Mayan Indians in Central America and Pacific Islanders also discovered how to make paper, but their knowledge never spread to the rest of the world. For centuries, all paper was made by hand. Rags were the main material. Then a French scientist discovered that people could make paper from wood, too. Finally, in the eighteenth century. a Frenchman invented a machine to make paper from wood.
Question: Who discovered how to make paper?
Options: (A) The Chinese. (B) The Pacific Islanders. (C) The Mayan Indians. (D) All of the above.
[A]: D

[Q]: Article: A year ago, I paid no attention to English idioms, though my teacher emphasized the importance again and again. But soon, the importance of English idioms was showed in an _ experience. One day, I happened to meet an Englishman, on the road, and soon we began to talk. As I was talking about how I was studying English, the foreigner seemed to be astonished, gently shaking his head ,shrugging his shoulders, saying, "You don't say! You don't say!" I was puzzled, I thought, perhaps this is not a proper topic.Well, I had better change the topic. So I said to him, "Well, shall we talk about the Great Wall? By the way, have you ever been there?" "Certainly, everybody back home will laugh at me if I leave China without seeing it. It was magnificent(,)." He was deep in thought when I began to talk like a tourist guide. "The Great Wall is one of the wonders in the world. We are very proud of it. " Soon I was interrupted again by his order "You don't say!" I couldn't help asking, "Why do you ask me not to talk about it?" "Well, I didn't request you to do so," He answered, greatly surprised. I said, "Didn't you say you don't say?" Hearing this, the Englishman laughed to tears. He began to explain, "You don't say actually means really? It is an expression of surprise Perhaps you don't pay attention to English idioms" Only then did I know I had made a fool of myself. Since then I have been more careful with idiomatic expressions.
Question: A year ago, I did not pay attention to English idioms because _ .
Options: (A) English idioms were too difficult to master (B) I care little about the teacher's instruction (C) My teacher didn't emphasize the importance (D) I had no interest in English learning
[A]: B

[Q]: Article: If you have a chance to go to school in prefix = st1 /America, you should keep the following in mind: *If a teacher asks you a question, you are expected to give an answer. If you do not understand the question, you should raise your hand and ask the teacher to repeat the question. It is all right to tell the teacher that you do not know the answer. Then he or she knows what you need to learn. *There is no excuse for not doing your homework. If you are absent ,you should call your teacher or your classmates and ask for the assignment. It is your responsibility to find out what homework you have missed. *It is impolite to eat, drink or chew gum during class. This is allowed for the break. Removing one' s shoes in the classroom is also not polite. *You must not be absent on a test day. If you are seriously ill, you must call and let the teacher know you will not be there for the test. If your teacher allows a make-up test, you should take the test within one or two days after returning to class. *It is rude to be late. If you must come in late, be sure to do it quietly by having your books and papers out of your bag, then go to your seat and sit very quietly. In the U. S., it is not necessary to knock before you enter the classroom. Most teachers will give you a low grade if you are often late. *Copying another student' s test or paper is never acceptable. It is called cheating. Students who cheat are kicked out in most schools.
Question: What is the purpose of the passage?
Options: (A) To introduce some American classroom customs. (B) To explain how to communicate with others in America. (C) To introduce some social manners in America. (D) To help you learn more about American culture.
[A]:
A