Shortly after implantation the blastocyst wall, the trophoblast, consists of two layers of cells.植入之后不久,胚囊的壁, 即滋养细胞含有两层细胞.Microchips are convenient, safe, and reliable. Implantation is simple and routine.微芯片是方便 、 安全和可靠的....
We swallowed the chocolates in one gulp, licking our lips.我们一口吞下了巧克力，满意地咂着嘴。She folded up her letter, licking the envelope flap with relish.她把信折好，用力舔了舔信封的折口。They gave us a hell of a licking.他们把我们打得落花流水。...
热力学是很难教的一门课。Thermodynamics is a hard course to teach.学券会增加不平等,因为最难教的孩子将会被甩在后面.Vouchers would increase inequality because children who are hardest to teach would be left behind....