She has a gift for creating an atmosphere for her students ________ allows them to communicate freely

with each other.     [ ]

A. where      

B. which      

C. what        

D. who  

以（）等方式通过银行办理对境外付款业务时，必须填报“对外付款/承兑通知书”。

A、电汇

B、信用证

C、托收

D、保函