【问】 (A) He worked at his biology.

(B) He worked on his biology.

上面两个句子有无区别?

【答】 上面两个句子在意义上并没有什么区别。只是work at仅仅用于英国英语，而work on则既用于美国英语，又用于英国英语。

She is working her new play. (CGEL)

她正在努力写她的新剧本。

1. He's working at a new invention. (Palmer)

他正在努力搞一项新发明。

2. We were working on a new generator. (Cronin)

我们正在研究一种新的发电机。