替人作保

例句：

1. 1. The company guarantees a refund if the product is faulty.
   如果产品有缺陷，公司将提供退款。
2. 2.He guaranteed his word to me that he would come back for the meeting.
   他向我保证他会来参加会议。
3. 3. The bank guarantees all deposits up to a certain amount.
   银行对所有的存款都进行担保。