Noun:

1. double-walled stage of the embryo resulting from invagination of the blastula; the outer layer of cells is the ectoderm and the inner layer differentiates into the mesoderm and endoderm

Gasil伽矽尔(硅胶)gasn.煤气；气体；汽油；空话vt.使吸入毒气；毒(死)；给 ... 加汽油vi.空谈；加汽油gas-phase process气相法gas recovery design采气设计gas sample scrubber气样洗涤器gas flow rate index气流速度指数gas-particle flow气固两相流gas-press welding气压焊gas operated weapon气退式武器gas-liquid mixing气液混合gas-fluidized bed气固流化床gastroduoenal ulcer胃十二指肠

1. The resulting gastrula consists of an outer ectoderm, an inner endoderm, and a mesoderm layer positioned between them.
   最终原肠胚由一个外肠胚，内肠胚，和一个中肠胚构成。