Zhao Ye's purchase of jade bracelets is a contractual act with undetermined validity. Liu Lan has the right to return the jade bracelet. The reason is that the contract concluded by a person with capacity for conduct is not suitable for his age, intelligence and mental health, and the contract is valid after ratification by the legal agent. And the contract belongs to the contract whose validity is to be determined before the respondent's ratification in law. If the parents refuse to approve, the contract is invalid. ?

Zhao Ye spent 4800 yuan to buy a jade bracelet, which is a civil act and the amount of the subject matter is relatively large. Not suitable for his age and intelligence, he must obtain the consent or ratification of his parents. Because his mother refused to approve the contract, it was invalid. As the contract is invalid, his mother Liu Lan has the right to demand the return of the jade bracelet.