Mesectoderm
中外胚层
🗣️ 情景例句
Your favorite people?
你喜欢的人？
He has come to be recognized as an expert in the problem of overpopulation and food supply.
由于他的经验促使他终于成为了公认的人口过剩和食物供应问题的专家。
From 1830 onwards in the USA and from about 1870 in Canada, settlers began to move westwards and to take possession of the plains as their own.
美国自1830年起，加拿大从1870年左右起，殖民者开始向西迁移，并把平原据为己有。