他们未能经济地经营电话网络.They were unable to run the telephone network economically.产生激光光子的费用太高,因此,不能用它很经济地制造出大多数化合物.Producing laser photons is too expensive to make most compounds economically.目的是使树冠保持在一定的高度和宽度的范围内,更经济地管理.The purp...
The explosives can be detected for the impact force of their deflagration with the modified cantilever.为了更进一步提高检测灵敏度,本文还提出了一种改进型悬臂梁的研制.In this paper , film magnetostrictive coefficient measurement system was designed bas...