A good calculating model of tractor economical life is no use, if there is no real, reliable data.
一个再好的拖拉机经济寿命计算模型，如果没有真实、可靠的数据，也是枉然。
They are thought to have leapt together with two rucksacks, one holding the body, the other filled with some of the child's favourite cuddly toys and a model tractor.
据推测，他们双双跳崖时携带着两个帆布包，一个装着儿子的遗体，另一个装着孩子心爱的抱抱玩具，还有一部玩具拖拉机。
The model can be used to analyze the effects of tractor and soil strength parameters on tractor performance, It is a useful tool for optimizing tractor performance in the field.
该模型可用来模拟田间试验、研究土壤强度和拖拉机参数对拖拉机作业性能的影响，对拖拉机使用性能的研究将起到一定的作用。
应用推荐