短语词组短语ploughshare bone 尾综骨trapezoidal ploughshare 梯形犁铧Ploughshare Tortoise 安哥洛卡象龟;犁头龟trench ploughshare 开沟犁犁铧underpoint suction in throatof ploughshare 垂直第二犁铧 返回 ploughshare