Discuss pollution with your child, emphasizing how nice a clean street, lawn, or park looks.和孩子讨论污染问题,强调清洁的街道、草地或公园有多么美丽。He listened in silence as Niccolini rattled on, emphasizing his remarks with one hand and steering ...
In this paper, a discrete stage - structured epidemical model is proposed and studied.本文主要讨论了离散的阶段结构传染病模型.OBJECTIVE To explore the administration measures of air condition usage in SARS epidemical period.目的研究传染性非典型肺炎流行期间...