girl是可數名詞還是不可數名詞?

例句：

Don was deep in conversation with the girl on his right.

唐與他右邊的女孩在專心交談。

Get dressed now, there's a good girl.

現在把衣服穿好，乖孩子。

He introduced me to a Greek girl at the party.

他在聚會上介紹我認識了一位希臘姑娘。

You wouldn't know what it means ─ it's a girl thing.

你不會知道那是什麼意思，那是女孩子家的事。