（请在使用前对文本的时效性进行确认，内容以全国人大、国务院等公报为准）
第五百一十二条 通过互联网等信息网络订立的电子合同的标的为交付商品并采用快递物流方式交付的，收货人的签收时间为交付时间。电子合同的标的为提供服务的，生成的电子凭证或者实物凭证中载明的时间为提供服务时间；前述凭证没有载明时间或者载明时间与实际提供服务时间不一致的，以实际提供服务的时间为准。
Article 512
Where the object of an electronic contract concluded through internet or other
information network is the delivery of goods and the goods are to be delivered
by express delivery services, the time of delivery is the time of acknowledging
receipt of the goods by the recipient. Where the object of the said electronic
contract is the provision of services, the time for provision of the service is
the time stated in the automatically generated electronic certificate or
physical certificate. Where there is no time stated in such a certificate or the
time stated therein is inconsistent with the actual time for provision of the
service, the actual time for provision of the service shall prevail.
电子合同的标的物为采用在线传输方式交付的，合同标的物进入对方当事人指定的特定系统且能够检索识别的时间为交付时间。
Where the subject matter of the said electronic contract is delivered by online
transmission, the time of delivery is the time when the subject matter of the
contract enters the specific system designated by the other party and can be
searched and identified.
电子合同当事人对交付商品或者提供服务的方式、时间另有约定的，按照其约定。
Where the parties to the said electronic contract agree otherwise on the mode
and time of delivery of goods or provision of services, such an agreement shall
be complied with.
第五百一十三条 执行政府定价或者政府指导价的，在合同约定的交付期限内政府价格调整时，按照交付时的价格计价。逾期交付标的物的，遇价格上涨时，按照原价格执行；价格下降时，按照新价格执行。逾期提取标的物或者逾期付款的，遇价格上涨时，按照新价格执行；价格下降时，按照原价格执行。
Article 513
Where a government-set or government-guided price is adopted in a contract, if
the said price is adjusted within the delivery period agreed in the contract,
the contract price shall be the price as adjusted at the time of delivery. Where
an overdue delivery of the subject matter occurs, the contract price shall be
the original price if the price rises at the time of delivery, or the price as
adjusted if the price falls at the time of delivery. Where a delayed collection
of the subject matter 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.
第五百一十四条 以支付金钱为内容的债，除法律另有规定或者当事人另有约定外，债权人可以请求债务人以实际履行地的法定货币履行。
Article 514
Where an obligation is payment of money, unless otherwise provided by law or
agreed by the parties, the creditor may request the debtor to perform the
obligation by the lawful currency of the place of actual performance.
第五百一十五条 标的有多项而债务人只需履行其中一项的，债务人享有选择权；但是，法律另有规定、当事人另有约定或者另有交易习惯的除外。
Article 515
Where a contract has multiple objects and the debtor is required to perform only
one of them, the debtor has the right of choice to select the object to perform,
unless otherwise provided by law or agreed by the parties, or otherwise
determined by the course of dealing.
享有选择权的当事人在约定期限内或者履行期限届满未作选择，经催告后在合理期限内仍未选择的，选择权转移至对方。
Where the party with the right of choice fails to make selection within the
agreed period or upon expiration of the period of performance, and still fails
to make selection within a reasonable period of time after being demanded, the
right of choice shall be shifted to the other party.
唐诗宋词 全唐诗 唐诗300首 史记 孔子 孟子 四书五经 论语
（请在使用前对文本的时效性进行确认，内容以全国人大、国务院等公报为准）