The original valid documents and commercial invoices should be kept by the financial institutions that conduct foreign exchange transactions for the enterprises.

正本有效凭证和有效商业单据交给为企业办理付汇的金融机构留存。

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Smith says that by subcontracting some of the work abroad--for example, the intake manifold in a car's air system--these contractors can add 20 points to that gross margin, and that's after paying Smith his fee of 5% to 7% of the foreign invoices.

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