Converting a web page to a sharable pdf file is a long and arduous job .
将网页转换成一个可分享的pdf文件已一个漫长而且费尽的过程。
As a result , teachers can establish , manage and maintain their own specific e-learning environment more easily and flexibly by this virtual classroom system . It also makes the teacher 's learning resources and instructional strategies sharable to each other .
