Polycladin
波来克黄素
🗣️ 情景例句
It probably means he's clearing his throat.
也许表示他正在清喉咙。
It always take time to get used to a new place.
初来乍到，总要过些时候才会习惯的。
In this way, we have learned all that we know of the laws of astronomy,
例如，用这种方法，我们完全掌握了天文学的规律。