软X线摄影的管电压值应为()。
A.10~20kY
B.20~40kY
C.45~50kY
D.55~60kY
E.65~70kY
参考答案:B
解析:
软组织摄影20~40kV。
34. A note was on the blackboard ______ “All those who have a fever must leave school right now”.
A.on which was written
B.said
C.read
D.Reading
赫茨伯格认为,满足比较低级的需求的因素称为()。
A.保健因素
B.激励因素
C.临近因素
D.浅层因素