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第六百三十四条 分期付款的买受人未支付到期价款的数额达到全部价款的五分之一，经催告后在合理期限内仍未支付到期价款的，出卖人可以请求买受人支付全部价款或者解除合同。
Article 634
Where a buyer under an installment contract fails to make payment and the unpaid
amount reaches one-fifth of the total price, if the buyer still fails to pay the
due installment amount within a reasonable period of time after being demanded,
the seller may request the buyer to pay the total sum or he may rescind the
contract.
出卖人解除合同的，可以向买受人请求支付该标的物的使用费。
The seller who rescinds the contract may request the buyer to pay a fee for the
use of the subject matter.
第六百三十五条 凭样品买卖的当事人应当封存样品，并可以对样品质量予以说明。出卖人交付的标的物应当与样品及其说明的质量相同。
Article 635
The parties to a sale by sample shall seal up the sample and may make
specifications of its quality. The subject matter delivered by the seller shall
be identical in quality with the sample and its specifications.
第六百三十六条 凭样品买卖的买受人不知道样品有隐蔽瑕疵的，即使交付的标的物与样品相同，出卖人交付的标的物的质量仍然应当符合同种物的通常标准。
Article 636
Where a buyer to a sale by sample is unaware of the sample’s latent defects,
even if the subject matter delivered is identical with the sample, the quality
of the subject matter delivered by the seller shall still conform to the general
standard for the goods in the same category.
第六百三十七条 试用买卖的当事人可以约定标的物的试用期限。对试用期限没有约定或者约定不明确，依据本法第五百一十条的规定仍不能确定的，由出卖人确定。
Article 637
The parties to a sale on trial use may agree on a period for trial use of the
subject matter. Where there is no agreement between the parties on the period
for trial use or the relevant agreement is unclear, if the period for trial use
cannot be determined according to the provisions of Article 510 of this Code, it
shall be determined by the seller.
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