手工氧气切割的参数通常根据（）进行选择。
A、割嘴号码
B、割嘴孔径
C、切割厚度
D、氧气压力
参考答案：C
As soon as Mr. Li came in, he asked Joan to ________ the books around the class.
A．give up
B．give in
C．give out
D．give off
简述逐孔爆破技术原理。
