下列哪项不是急救工作人员主要培训内容（）？
A、院前急救技术
B、急诊心肺复苏术
C、心导管技术
D、心理学
参考答案：C
—Why not talk with your parents about your willingness to attend Peking University Summer Camp?
—I tried __________to get them to listen to me.
A．in time
B．in vain
C．in need
D．in case
在图所示的哪种做法的目的增大压强的是[ ]
A.
B.
C.
D.
