诊断梅尼埃病的甘油试验所用甘油的浓度为________。
参考答案：50％
He went back to the hall to try his__________at finding his lost gold watch,but never found it. [ ]
A. fortune
B. best
C. result
D. hard
管道吹洗时，一般应该遵循（）依次进行吹洗。
A、干管、支管、主管、疏排管
B、主管、干管、支管、疏排管
C、支管、干管、主管、疏排管
D、疏排管、干管、支管、主管
