It's Sunday morning. The students of Class 3 are cleaning their classroom. Miss Huang is their teacher. She is working with them. The students are busy. Some are carrying water;some are cleaning the windows;others(其他人)are sweeping the floor. Zhang Hua is putting up(张贴)a map on the wall. It is a map of China. Wang Fei and Wei Qing are mending(修理)some broken chairs. The students are listening to the radio while(当……的时候)they are working. The students are very happy.