A credit card is very useful when you go traveling.
当然旅游的时候,信用卡很有用。
Could you lend me ten dollars?I left my wallet at home.
你能借给我10美元?我把钱包留在家了。
and there is a very firm rule that the bank has no right or authority to pay out a customer's money on a cheque on which its customer's signature has been forged.