He is vacuuming a rug in the sitting room.他在起居室里用吸尘器打扫地毯.L am vacuuming the floor now and have several shirts to iron.我正在用真空吸尘器清理地板,还有好几件衬衫要熨.But a wide - open floor adds only a few seconds the vacuuming chore.但是,广泛的开放式购...
Thumbing a lift had once a carefree, easy-going image.伸手搭便车曾经给人以轻松随意的形象。I went out onto the road to start thumbing.我走到公路上,竖起拇指要求搭车.Thumbing the book, he found a maple leaf in it.他匆匆翻了一下书, 找到一片枫叶....
早期研究已证实鞣花酸具有防紫外线作用.Earlier studies have suggested it has a photo protective effect.浆果富含鞣花酸, 研究表明它可以抗癌.And berries contain ellagic acid, which some studies show may fight cancer.研究了用紫外分光光度法测定鞣花酸含量的一种新方法.A new method for d...