半衰期长的同位素试剂及其实验废弃物必须送具有资质的单位进行处理。
参考答案：对
The soldiers were fighting bravely_____their people__________the invaders. [ ]
A. with; for
B. for; against
C. back; with
D. out; with
锅炉热效率中，机械不完全燃烧损失受哪些因素影响？降低机械不完全燃烧损失的方法有哪些？
