1. (形势、规定或法律)强迫，迫使
    If you are obliged to do something, a situation, rule, or law makes it necessary for you to do that thing.

    e.g. The storm got worse and worse. Finally, I was obliged to abandon the car and continue on foot...
           暴风雨愈发猛烈，我最终不得不弃车步行。
    e.g. This decree obliges unions to delay strikes.
           该法令迫使工会推迟罢工。

2. 施恩惠于；帮…的忙
    To oblige someone means to be helpful to them by doing what they have asked you to do.

    e.g. If you ever need help with the babysitting, I'd be glad to oblige...
           如果你什么时候需要找人照看孩子，我很乐意帮忙。
    e.g. We called up three economists to ask how to eliminate the deficit and they obliged with very straightforward answers...
           我们打电话给3位经济学家询问如何消除赤字，他们坦率地给予了答复。

3. 感激不尽;不胜感激
    People sometimes use obliged in expressions such as 'much obliged' or 'I am obliged to you' when they want to indicate that they are very grateful for something.

    e.g. Much obliged for your assistance...
           对您的帮助我不胜感激。
    e.g. Thank you very much indeed, Doctor, I am extremely obliged to you.
           大夫，太感谢您了，您真是我的大恩人。

4. 如蒙…将不胜感激;劳驾…好吗
    If you tell someone that you would be obliged or should be obliged if they would do something, you are telling them in a polite but firm way that you want them to do it.

    e.g. I would be obliged if you could read it to us.
           您若能把它读给大家听，我将不胜感激。