目前我国的天然气净化工艺较国外水平（）。
A、先进
B、远远落后
C、基本赶上
D、无法比较
参考答案：C
Because our work is very busy, so we need to relax at midday.
A．We are very busy
B．Our work being busy.
C．Our work so very busy
D．Because our work so very busy,
在光线不足的作业场所及夜间作业的场所均应有足够的（）。
