Osteogenin
成骨素
🗣️ 情景例句
we would go down to the beach and catch crabs,
我们走到海边抓螃蟹，
One must draw the line somewhere.
人之所为，总有限度。
Don't worry! We won't leave before nine. We'll wait for you outside the school gate!
别担心！9：00前我们不会出发。我们将在学校的大门外等你！