题目

阅读短文，选择正确的答案及回答问题。Mr. and Mrs. Brown lives in New York. They are now working in Shanghai. Mr. Brown is an engineer(工程师) and Mrs. Brown is an English teacher. They have a son(儿子) and his name is Jack. Jack lives in Shanghai with his parents. But he can only(仅仅, 只) speak English. Mr and Mrs. Brown want him to learn some Chinese. So they send Jack to a primary school(小学). Jack is now in Grade Three. He likes to play with Chinese children every day. He has many good friends at school. They teach him Chinese after class. Jack can listen to Chi若点P（）、Q（）关于原点对称，则=_____________。