题干: 下列债务凭证中属于银行信用的是( )。
A．企业债券
B．银行债券
C． 银行票据
D．银行存单
参考答案：B,C,D
It's raining heavily. We have to ______ the sports meet. [ ]
A. put off
B. join in
C. hold on
D. take part in
简述硬膜外血肿
