work at   (TTS發音)

1. be engaged in 致力于；從事于；鑽研

    He is working at a new subject. 他正在研究一門新的學科。

    You will have to work at the weak points if you want to pass the examination. 你要想考試過關就得在你的薄弱環節上下功夫。

2. do sth. with effort 在…上下功夫

    You'll crack this problem if you really work at it. 只要你下功夫就能解決這個問題。