高含硫油气井是指地层天然气中硫化氢含量高于（）的井。
A.10ppm
B.100ppm
C.20ppm
D.30ppm
参考答案：A
It ________________the job yesterday.
A．took me two hours to finish.
B．cost me two hours to finish
C．spent me two hours finishing
D．took me two hours finishing
安慰剂
