Poly ( vinyl alcohol ) has been protected against radiation by benzalation and benzoylation.聚乙烯醇 的耐辐解可通地苄叉化和苯甲酰化提高.Poly alcohol has been protected against radiation by benzalation and benzoylation.聚乙烯醇的耐辐解可通过苄叉化和苯甲酰化提高.M...
调查发现一层地下的横梁大面积腐烂。Investigations had revealed extensive rot in the beams under the ground floor.把横梁用托架和螺丝固定。Fix the beam with the brackets and screws.横梁上的负荷比它能承受的要大得多.The load on this beam is more than it will bear....
The research effort has focused on tracing the effects of growing levels of five compounds...研究重点追踪了5种化合物含量上升的影响。The public is urgently requested to assist police in tracing this man.紧急要求公众帮助警方追踪此人。curve tracing曲线描迹法, 曲线...