pay的过去式例句：
1. Interest is paid monthly. Three months' notice is required for withdrawals.
利息按月支付。提款须提前3个月通知银行。
2. Sandra was determined to become a doctor and her persistence paid off.
桑德拉决心成为医生，她的坚持取得了成功。
3. He paid for and was assigned a cabin in first class.
他付完钱后被安排到了头等舱。
4. He is cagey about what he was paid for the business.
他对自己在这桩买卖中所得的报酬不愿多提。