TBI(全身照射)现在常用的技术要求是()
A.延长距离2-3米
B.机架旋转45度
C.治疗头旋转90度
D.照射野的对角线平行于患者的长轴方向
E.垂直照射
参考答案:D
Only when he returned from the exchange program ________ how much he enjoyed it.[ ]
A. he knew
B. he had known
C. did he know
D. had he known
下列关于风险偏好的说法正确的是( )。
A.风险回避者一定会选择风险低的资产
B.一般的投资者和企业管理者都是风险回避者
C.当预期收益率相同时,风险中立者会偏好于具有低风险的资产
D.当预期收益率相同时,风险追求者会偏好于具有高风险的资产