他轻轻松开油门杆，轮船开始缓缓前行。He gently opened the throttle, and the ship began to ease forward.伦纳德在温室里悠然自得地给西红柿绑上撑杆。Leonard pottered round the greenhouse, tying up canes for the tomatoes.压下挡杆，直到听到挡挂好。Press the lever until you hear ...
This pushing - in of cells marks the start of gastrulation.细胞的这种向里推进标志着原肠胚形成的开始.The outer layer of a blastula that gives rise to the ectoderm after gastrulation.外胚层囊胚的外层,在原肠胚形成之后生后外胚层组织....