Ectoderm
n. 外胚层, 外层\\n[医] 外胚层
🗣️ 情景例句
Sure, but never before have we had payment in RMB.
当然可以，不过我们从来没有用过人民币付款。
He who does not advance falls backward.
不进则退。
like adolescents they stand before the mirror,
犹如希腊神话中那位漂亮少年，