企业债券持有人无权( )。
A．收回本金
B．以债券作抵押
C．转让债券
D．参与企业经营管理
参考答案：D
He was looking impatient at the visiting salesman, who showed no signs of getting ready to leave.
A．patient
B．patience
C．impatience
D．impatiently
下列哪个不是快速生成树的状态（）.
A、丢弃
B、学习
C、转发
D、监听
