如何预防青霉素过敏。
参考答案：
①询问过敏史；②皮试；③注射后观察30min；④准备抢救药品及器材。治疗首选：im0。1%肾上腺素0。5～1ml。
Various efforts over the centuries _________ to predict earthquakes to reduce the damage.
A．are being made
B．have been made
C．were made
D．were being made
货物总重心在车地板上的投影位于车地板（），且偏离超过限度即为偏载。
