4个数字3个为一组有多少组简介：After two more regular classes, it was time to attend morning exercises at nine-twenty. Originally, every grade had to do morning exercises, but the school did not have many venues that could accommodate three grades.
After two more regular classes, it was time to attend morning exercises at nine-twenty. Originally, every grade had to do morning exercises, but the school did not have many venues that could accommodate three grades.
