1. He immediately telephoned the police and informed them that two students dressed up as workmen were tearing up the road with a pneumatic drill.
    马上打电话报告警察，说有两个学生装扮成工人，正在用风钻破坏路面。

2. It cuts a clean cylinder of rock, from which can be seen the strata the drill has been cutting through.
    它切割出一块表面光滑的圆柱体石头, 从这石块上可以看出钻头在切割的岩层.

3. It cuts a clean cylinder of rock, from which can be seen the strata the drill has been cutting through.
    这种钻头能切割一段光滑的圆柱形岩石，从中能看出所钻透的地层。

4. If they knew how difficult it was to drill through the hard rock, they would lose heart.
    如果他们知道了钻透那坚硬的岩石有多么困难，他们会丧失信心的。