useful

• The streaked plate is in general the most useful plating method .
  划线平板法是最有用的平板法。
• He is a useful bat .
  他是个优秀的击球员。
• The canal has proved useful to the county in many ways .
  这条水渠给这个县带来的好处是多方面的。
• The latter studies are extremely useful to the analyst .
  后者的这些研究对于分析工作者极为有用。
• It is useful in discussing the nature of sedimentary deposits .
  它在讨论沉积物的性质时是有用的。
• Methods were tried in case a useful tool should emerge .
  试验了各种方法，以便确定哪一种是有效的。
• Newton's law of universal gravitation has been extremely useful .
  牛顿的万有引力定律是极其有用的。
• It will be useful to summarize the relevant gaussian formulae .
  有必要概括地讲一下有关的高斯公式。
• The march would consume half of the useful life of the vehicle .
  此次长途跋涉将过于损耗车辆的寿命。
• Two alternative systems are useful to avoid this stalemate .
  此时采用下列两种系统之一便可加以解决。