给多音字注音并组词。

剥 ____  ____     落 ____  ____

   ____  ____       ____  ____

求证：c²＝a²＋b²_.

    My friend Tom lives on Sun Street. It is near his school. He usually goes to school on foot. But sometimes he goes to school by bike. His father is a doctor. He goes to work by car. His mother is a teacher. She teaches English. She goes to work by metro. Today is Sunday. Tom doesn't have any lessons. He wants to go to Nanjing by train.