(朗朗)的书声, (动听)的歌声, (发自肺腑)的心声,(气氛活跃)的课堂, (繁重)的劳动, (愉快)的郊游, (宽大)的操场,
(朗朗)的书声, (欢乐)的歌声, (发自肺腑)的心声,(气氛活跃)的课堂, (繁重)的劳动, (愉快)的郊游, (中学)的操场,