The infra - red spectra of quinones present a number of interesting features.醌类的红外光谱具有一些有趣的性质.Ethylene and trans - dichloroethylene are both inactive in the infra - red in this region.乙烯和反式二氯乙烯在红外光谱的这个区域都无活性.Infra - red ...
珍妮花: 如果你认为那是浮板的话,你会淹死的.Jennifer: You'll drown if you think that's a kickboard.涵涵上游泳课又有了新的爱好, 抓浮板踢水.Helen found a new toy in her swimming lesson, kick board.将浮板抓在手上并踢水.Hold the kickboard in your hands, and kick....