阅读理解
C
Welcome to Class 4, Grade 7. This is our classroom. There are twenty boys and twenty -four girls in the classroom. The teacher's desk is in the front of the classroom. There is a big blackboard on the front wall and a small blackboard on the back wall. There are two maps on the wall. One is a map of China and the other is a map of the world．There are some photos on the wall. There are some flowers by the windows. Our classroom is very beautiful.
，则它的极坐标是 （ ）
