constrain (1) students to use abacus a.强迫销售员道歉 ______ (2) criminals to live in backwater b.强迫学生使用算盘 ______ (3) teachers to study CAD c.强迫犯人住在穷乡僻壤 ______ (4) workers to work extra hours d.强迫教师学计算机辅助设计 ______ (5) the salesman to apologize e.强迫工人加班 ______