The machine needs to be modified before it can take the new cartridges.机器需要先改造才能装配这些新墨盒。Forensic officers pace up and down the road, searching for bullet holes and spent cartridges.法医们沿这条路走来走去，寻找弹孔以及废弹壳。Several spent cartridges have already been found.几个空弹壳已经被找到。