He________English since he graduated from college and he is now even more interested in teaching it. [ ]

A. taught    

B. was teaching

C. has been teaching  

D. had taught

下列属于金融市场发展对商业银行的挑战的是（）

A、对银行资产和负债的价值影响会不断加大

B、银行风险管理难度会加大

C、会放大银行的风险事件

D、会减少银行的资本来源以及优质客户的流失

E、会造成银行体制结构的崩溃

F、不利于银行的长期发展