颈椎的特点是（）。
A.肋凹
B.横突孔
C.棘突水平伸向后方
D.前弓和后弓
E.齿状突
参考答案：B
In the past ten years, the ________mountain climber _________ a lot from his own adventurous _______
A．experienced; experienced; experience
B．experience; experienced; experiences
C．experienced; has experienced; experiences
D．experience; has experience; experience
保险合同主体的权利与义务的变更属于（）。
A．保险合同客体变更
B．保险合同主体变更
C．保险合同内容变更
D．保险合同标的变更
