对 聚亚 磺酰氨基酰胺 ( PSAA ) 作为新型抗氧化反渗透膜材料的可能性,以及聚合条件和成膜条件对膜性能的影响作了初步研究.The possibility poly ( sulfonamido ) amide ( PSAA ) a new reverse osmosis membrane material with anti - oxidation properties was preliminary studied....
I let the horse drop his head to crop the spring grass.我让马低下头啃吃春天的青草。The windows overlooked a lawn of tall waving grass.窗户外边是一块草地，高高的草随风摇摆。Their four children turn cartwheels in the grass as we talk.我们说话的时候，他们家的4个孩子在草地上玩...
He was convinced that doctors and dentists knew best.他确信医生和牙医最清楚该怎么做。Children often fight shy of dentists.孩子们常常害怕看牙医.These figures are arrived at on the basis of dentists' receipts for 1991-1992.这些数字是根据1991至1992年间的牙...