Betulinic acid
[机] 桦木酸
🧩 词语组成解析
🗣️ 情景例句
I can't wait till he's just a little older.
我迫不及待地希望他长大些。
I sometimes stay up till midnight.
我有时候熬到半夜。[一般现在时]
It was very old and precious even then.
却使在当时，它也属历史悠久的珍奇之物。