to have an obligation to sb有义务(或责任)照顾某人
Every community had a moral obligation to its own poor.每个社区在道义上都有责任照顾本社区的贫困居民。
You have the obligation to your family to choose carefully.你有责任为家人仔细选择。
I have an ethical and a moral obligation to my client.我对我的当事人负有道义上的责任。