细胞的这种向里推进标志着原肠胚形成的开始.This pushing - in of cells marks the start of gastrulation.外胚层囊胚的外层,在原肠胚形成之后生后外胚层组织.The outer layer of a blastula that gives rise to the ectoderm after gastrulation....
通往驻防地的道路上地雷密布。The approaches to the garrison have been heavily mined.派了一百名士兵在城里驻防.A hundred soldiers were garrisoned in the town.驻防的军队是保持警惕的, 但是人数毕竟太少了.The garrison was alert, but too few....
由二苯并-1,3-二氧杂 - 环辛烷 -2- 羧酸经两步反应制得, 总收率70%.It was prepared by the reaction of 12 H - dibenzo [ d , g ] [ 1,3 ] dioxocin - 6 - carboxylic acid with acetoxime.地衣是一类独特的生物有机体,其体内合成了多种特殊的次生代谢产物,主要为缩酚酸、缩酚酸环醚 、 缩酚酮、二苯并呋喃等类化合物.A l...
他们需要卡车把产品运往这一广阔地区里的各个地方.They needed trucks to distribute their produce over this wide area.各个学院和其他建筑广阔地散落在全城和市郊.Its colleges and other buildings are scattered widely throughout the city and its outskirts....