被污染的废物经常被随意倒掉,周边土地因此而变得很贫瘠。The polluted waste is often dumped, making the surrounding land infertile.黑麦耐贫瘠的酸性土壤。Rye is tolerant of poor, acid soils.土壤这样贫瘠,植物能获得足够的养分吗?Can plants obtain adequate nourishment from such poor...
在试验段中装有两个平行六面体试件.Two sample parallelepipeds are located in the test section.我们现在在三维应力分析中采用四面体单元和六面体单元.We can now use tetrahedron and hexahedron elements in three - dimensional stress analysis.同高的平行六面体(的体积)之比等于其底面(积)之比.Pa...