The theater emailed ticket holders that an understudy would perform tonight's leading role.

劇院寄電子郵件通知持票觀眾，今晚的主角將由替角演出。

During the meeting, the director asked each understudy to attend every rehearsal this month.

會議中，導演要求每位替角本月都要參加每一場排練。

The hiring manager posted an ad seeking two understudies for the touring musical.

招募經理刊登廣告，為巡迴音樂劇徵求兩名替角演員。