词汇	deep in a book
释义	deep in a book 专心阅读书籍
随便看	optically thickdiffusive optically thicker medium optically thick layers optically thick limit optically thick medium optically thickness optically thick plasma optically thin limit optically thin medium optically thinner medium optically thin plasma optically tracked optically transparent optically transparent medium optically transparent vitreous carbon electrode optically uniaxial Optically variable optically variable pigments optically violently variable quasar optically violently variable quasar, OVV quasar optically violent variables optically violent variablesovv optically visible object optical machine tool optical machine unit