Workers have just put the finishing touches on an ocean drilling vessel that is designed to bore to unprecedented depths and attain a long - held goal : penetrating the earth ' s rocky crust to the mantle 工作人员刚完成这艘海洋探测船的最后整备，它将要钻探达到空前的深度，并且完成科学家长久以来的目标：穿过地球的岩质地壳，达到地幔。
