“一炮三检”（），检查瓦斯浓度。
A、装药前
B、放炮前
C、放炮后
参考答案：A, B, C
在一定温度下，瓦斯压力升高，煤吸附瓦斯量将大幅度增加。
I have _______used to ________with chopsticks for almost one year.
A．got, eating
B．been, eating
C．got, to eat
D．been, to eat
