以下气体中哪一组属于煤矿中常见的有毒性气体（）。
A、CO和H2S
B、CH4和NO2
C、CO2和H2
D、N2和CH4
参考答案：A
It was in the village _____ we used to live ______ the film was made.
A．that; where
B．where; that
C．which; that
D．that; which
