就常用的45%MDEA溶液而言，其腐蚀速度远低于（）。
A.0.1mm/a
B.0.25mm/a
C.0.3mm/a
D.0.5mm/a
参考答案：A
With no one to in such a frightening situation, she felt very helpless. [ ]
A. turn on
B. turn off
C. turn over
D. turn to
吸入粉雾剂每揿主药含量应为标示量的
A．70%-130%
B．75%-125%
C．65%-135%
D．80%-120%
E．85%-115%
