obliged

I'd be much obliged if you'd hold the door for me.如果你能帮我拉着门，我很感激。

We felt obliged [=indebted] to them for all their help.我们很感激他们的这一切帮助。

You've been so helpful. We are much obliged. [=we are very grateful; we thank you very much]你一直这么帮忙，我们非常感激。