Where the basic conditions of contract undergoes a material change unforeseeable by the parties at the time of contracting which is not a commercial risk after the formation of the contract,rendering the continuation of the performance of the contract unconscionable for either party, the adversely affected party may renegotiate with the other party; and if the renegotiation fails within a reasonable time limit, the party may request the people's court or an arbitration institution to modify or rescind the contract. 合同成立后，合同的基础条件发生了当事人在订立合同时无法预见的、不属于商业风险的重大变化，继续履行合同对于当事人一方明显不公平的，受不利影响的当事人可以与对方重新协商；在合理期限内协商不成的，当事人可以请求人民法院或者仲裁机构变更或者解除合同。 The opposite party may raise, against the creditor, defenses against the debtor. 相对人对债务人的抗辩，可以向债权人主张。