wǒ我qù去xiǎo diàn小店mǎi买niú nǎi牛奶。niú nǎi牛奶wǔ kuài五块qián钱yì bēi一杯。wǒ我gěi给tā他qián钱,tā他gěi给wǒ我niú nǎi牛奶。wǒ我shuō说:“xiè xie谢谢!”niú nǎi牛奶zhēn真hǎo hē好喝!