1.got the surprise of their lives during their commencement ceremony.
commencement 毕业典礼
He was invited to speak at the commencement.
他受邀在毕业典礼上讲话 。
2.Mr Smith ended his speech by informing the 400 students that he would pay off their student loans and debt.
pay off付清
It would take him the rest of his life to pay off that loan.
他得用余生来还清那笔贷款 。