谢谢你的帮忙，我都不知道怎么报答你。

Xièxie nǐde bāngmáng, wǒ dōu bù zhīdào zěnme bàodá nǐ.

Thanks for your help—I don’t even know how to repay you.

妈妈说，只要我努力读书就是对她的报答。

Māma shuō, zhǐyào wǒ nǔlì dúshū jiù shì duì tā de bàodá.

Mom said that as long as I study hard, that’s repayment enough for her.

我买了一套房子给父母，以报答他们对我一直以来的付出和支持。

Wǒ mǎi le yí tào fángzi gěi fùmǔ, yǐ bàodá tāmen duì wǒ yìzhí yǐlái de fùchū hé zhīchí.

I bought my parents a house to repay them for all their effort and support over the years.