Anne usually was only willing to help those who suffered from the same disease as she did.
By means of __________ (being young and being old) the author reveals the advantages of being old.
由于受工作面、自由面的限制,以及控制开挖断面轮廓形状和尺寸的要求,按炮孔的作用可将炮孔分为掏槽炮孔、崩落炮孔和周边炮孔。()