In remote regions, the air is pure and the crops are free of poisonous insecticides.在偏远地区，空气很纯净，庄稼也不施用有毒的杀虫剂。Objective To find methods for testing quickly if there were organophosphate and carbamate in insecticides.目的快速检...
We use boldface type for vectors.我们用黑体形式表示矢量.Design problems, which represent challenging applications of the text material, are identified by boldface problem numbers.对于本教材中较难的设计问题用黑体字题号来标志.You can specify whether the f...
你如果把信封倒过来, 钥匙就会掉出.If you turn the envelope upside down, the key will fall out.她试了一下, 秘密的夹底果然开了, 里边掉出4封信.She tried it, the secret compartment opened, and out fell four notes.火炉里掉出一块炽热的煤把地毯烧了.A hot coal fell out of the fir...
薄薄的一层表土被冲走了。A thin layer of topsoil was swept away.那单薄的土地很快就失去了表土,成为沙粒和尘埃.The fragile land quickly lost its topsoil and became nothing but sand and dust.从工地挖出的表土须用于筑堤的石笼上.Topsoil excavated from the work site shall be app...