“lesson piece”簡單造句，lesson piece造句子

During this lesson, the teacher took out a frayed book with all the lesson pieces arranged according to difficulty, for choosing a new piece to study.

What demand point out is" software" that the here say not mean a concrete lesson piece, but should be a software of tool that faces to the course, include to take the terrace and multi-media databases of have the course special featureses.