network is the delivery of goods and the goods are to be delivered by express delivery services, the me of delivery is the me of acknowledging receipt of the goods by the recipient. Where the object of the said electronic contract is the provision of services, the me for provision of the service is the me stated in the automa c generated electronic cer cate or physical cer cate. Where there is no me stated in such a cer cate or the me stated therein is inconsistent with the actual me for provision of the service, the actual me for provision of the service shall prevail. Where the subject ma er of the said electronic contract is delivered by online transmission, the me of delivery is the me when the subject ma er of the contract enters the speci c system designated by the other party and can be searched and iden ed. Where the par es to the said electronic contract agree otherwise on the mode and me of delivery of goods or provision of services, such agreement shall be complied with. Ar cle 513 Where a government-set or government-guided price is adopted in a contract, if the said price is adjusted within the delivery period s pulated in the contract, the contract price shall be the price as adjusted at the me of delivery. Where an overdue delivery of the subject ma er occurs, the contract price shall be the original price if the price rises at the me of delivery, or the price as adjusted if the price falls at the me of delivery. Where a delayed delivery of the subject ma er or an overdue payment occurs, the contract price shall be the price as adjusted if the price rises, or the original price if the price falls. Ar cle 514 Where an obliga on is payment of money, unless otherwise provided by law or agreed by the par es, the creditor may request the debtor to perform the obliga on by the lawful currency of the place of actual performance. Ar cle 515 Where a contract has mul ple objects and the debtor is required to perform only one of them, the debtor has the right of choice to choose the object to perform, unless otherwise provided by law or agreed by the par es, or otherwise determined by the course of dealing. Where the party with the right of choice fails to make the choice within the agreed period or upon expira on of the period of performance, and s ll fails to make the choice within a reasonable period of me a er being demanded, the right of choice shall be shi ed to the other party. Ar cle 516 A party shall promptly no fy the other party when exercising the right of choice, and the object of the contract to be performed shall be ascertained at the me when such no ce reaches the other party. The ascertained object shall not be changed, unless otherwise consented to by the other party. Where one of the objects available for choice becomes impossible to perform, the party with the right of choice shall not choose such object to perform, unless the impossibility to perform is caused by the other party. Ar cle 517 Where there are two or more creditors, if the object is divisible and each creditor is en tled to the claim in propor on to his own share, then the claim is a claim by share; where there are two or more debtors, if the object is divisible and each debtor assumes the obliga on in propor on to his own share, then the obliga on is an obliga on by share. Where it is di cult to determine the share among the creditors with a claim by share or the debtors with an obliga on by share, each is deemed to have or assume an equal share. Ar cle 518 Where there are two or more creditors, and any or all of the creditors may request the debtor to perform the obliga on, their claim is a joint and several claim; where there are two or more debtors, and the creditor can request any or all of the debtors to perform the full obliga on, the obliga on is a joint and several obliga on. A joint and several claim or a joint and several obliga on shall be provided by law or agreed by the par es. Ar cle 519 Where it is di cult to determine the share of obliga on among the debtors assuming joint and several liabili es, each debtor is deemed to owe an equal share. A debtor assuming joint and several liabili es who has assumed obliga on in excess of his own share has the ti ti ti ft ti ti ti ti ti ti ti ti ti tt fi ti ti ti ti ti tt ti ti fi ti ti ti ti fi ti ft ti tt ti fi ti ti ti ti ti ti ffi tt ti ti ti ti ti ti ti ti ti ffi ti ti ti ti ti fi ti ti ti ti ti ti ti ti ti ti 57