This material is unshrinkable and colorfast after it 's washed .

这种面料洗后不缩水、不退色。

All the school teachers and administrators , especially teachers who teach audiovisual lessons have an unshrinkable duty to perfect the educational techniques .

学校的全体教师、管理干部和电教人员，对搞好教育技术工作都有着义不容辞的责任。