The revocation of a contract refers to the fact that the intention is untrue, and the cancellation of the right to cancel the contract that has entered into force. The contract with a reason for cancellation is called a revocable contract. Such contracts are mostly contracts established due to major misunderstandings. Contracts based on fraud, contracts based on coercion, etc. Are the following revocable contracts? ['A and B sign a pledge contract, stipulating that A cannot perform the contractual obligations as scheduled, then B takes ownership of the pledge.', 'Fund lending contract between A and B enterprises.', 'A evades court enforcement by giving his property to B.', "A needs money urgently for treatment, and B proposes to buy A's precious oil painting at a price nearly five times lower than the market price."]