巧克力是可數名詞還是不可數名詞英語

例句：

Would you like some chocolate cake?

你想來點兒巧克力蛋糕嗎？

Chocolate comes from the cacao tree.

巧克力來自可可樹。

What is your favourite chocolate bar?

你最喜愛的巧克力棒是什麼？