A pending-effect contract refers to a contract that has been established, but because it does not fully comply with the relevant requirements for entry into force, the validity of the contract has not yet been determined. Generally, it must be acknowledged by the authorized person to enter into force. In the following cases,. ['Xiao Ming, 10, sells the Rolex gold watch to 40-year-old Li.', '-year-old child army receives a bonus for invention.', 'Adult Zhang mistakenly bought the original oil painting as a genuine product.', 'Taxi drivers can increase car prices by 10 times by using a machine that is in urgent need of a car.']