be obliged to

例句：

1. 1. You are obliged to returnthe borrowed book by the end ofnext week.
   你下周初之前必须归还借来的书。
2. 2. He was obliged to acceptthe job offer because he had no otherchoice.
   他别无选择，只能接受那份工作邀请。
3. 3. Thecompany is obliged to providea safe working environment for itsemployees.
   公司有义务为员工提供一个安全的工作环境。