Bound to happen.注定的

bound to:必然, 不得不, 必须

The question is bound to come up at the meeting.

会上必然要讨论这个问题。

I'm duty bound to visit my old aunt.

我有义务去探望年老的姑妈。

so I owe you favor.我还欠你们一个人情

owe:欠（债, 钱, 人情等）

I owe a lot to my wife and children.

我很感激我的妻子和孩子。

You can take your time to pay the debt you owe me.

你欠我的债可以慢慢还。

扩展:owe to:把 ... 归功于 ...

His success does not owe to luck but ability.

他的成功应当归功于他的能力而不是运气。