Prospect Park, with its vast lake, is a magnet for all health freaks...拥有一大片湖区的普罗斯佩克特公园吸引着所有注重健康的人。Certain metals are attracted to a magnet.某些金属受磁石的吸引。The earth may be thought of as a gigantic magnet.整个地球可以想像为一块硕大无朋的磁石.F...
But the research on borehole deviation control is very few.但在井斜控制方面的研究还很欠缺.Borehole hydromining is a kind of safe and efficient new mining method.钻孔水力采煤是一种既安全、又能极大地提高资源利用率的新的采矿方法.There is some trouble in the borehole. Do...