Polyprotic acid
[化] 多元酸
🧩 词语组成解析
🗣️ 情景例句
At 4, but I have to leave by 3:00 to get there on time.
四点，不过我三点必须离开，才能准时到那里。
My friend spent his childhood in California .
我的朋友在加利福尼亚度过了他的童年。
Sure that I had passed, I was almost beginning to enjoy my test.
确信我已通过考试，所以我几乎开始喜欢起这次考试。