elementary net system

例句：

1. 1. Theelementary school has a large playground for childrento play on.
   小学有一个很大的操场供孩子们玩耍。
2. 2. The teacher explained the basic principlesof physics to the students.
   老师向学生们解释了物理学的基本原理。
3. 3. The elementaryschool is located in a quiet neighborhood.
   这所小学位于一个安静的社区。