—_____ are you staying in the countryside?       

—For more than one week.[ ]

A. How often

B. How long

C. How much

单位保证金存款是建设银行办理（）代客债券买卖等业务时收到的单位客户存入的保证金。

A.银行卡、担保

B.承兑、保函

C.开立信用证

D.代客外汇买卖