当井喷失控，井场硫化氢的浓度达到（）PPM，现场作业人员应按预案立即撤离井场。
A.200
B.500
C.150
D.100
参考答案：D
I will let you know as soon as I ___the tickets to Lang Lang's Piano Concert. [ ]
A. get
B. will get
C. am getting
D. got
在蒸汽管道上，设置疏水器的作用是什么？
