A circumstance referred to in this clause whether occurring prior to or after the formation of the contract shall give a right to suspension only if its effect on the performance of the contract could not be foreseen at the time of the formation of the contract 本条中的情况指无论合同缔结前后,双方有权延缓履行其义务是由于在形成合同时不能预见到合同的履行将会受到影响。