Mesectoderm
中外胚层
🗣️ 情景例句
and we probably won't be able to
而我们也许也一样不能
The years teach much which the days never know.
学问集年而成，而每日不自知也。
Until we are intelligent as to its laws and varieties,
直到我们理解了风俗的规律性和多样性，