When you write a letter or make a telephone call, your words 1a message. People communicate(沟通) with words. Do you think you can communicate2words? A smile3your face shows you are happy and friendly. Tears in your eyes tell 4that you are sad. When you 5your hand in class, the teacher knows you want to say something6ask questions. You shake（摇头） your head, and people know you are saying no. You nod（点头） and people know you are saying7.
Other things can also give some information. For example, a sign at the bus stop helps you to know which bus 8. A sign on the wall of your school helps you to find the library. Signs on doors tell you 9to go in or out.10you ever noticed that there are a lot of signs around you and that you receive message11them all the time?
People can communicate12many other ways.13artist can use his drawings to tell about beautiful mountains, about the blue sea and many other things. Books14 to tell you about all wonderful things in the world. They all help us to know 15 is going on in the world.
的最小正周期为
，若其图像向左平移
个单位后得到的函数为奇函数，则函数
的图像 （ ）
