It is a good idea, however, to request transaction certificates; and actually many US companies and their certifiers have this as a routine.

然而要求交易证明是一个不错的手段，而且实际上很多美国公司和他们的认证人员以这个作为例行手续。

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Certifiers (domestic manufacturers or importers) should be able to trace that component to its original component manufacturer.

认证方(国内生产商或进口商)应可以追溯到部件的最初生产商。

youdao

Certifiers (domestic manufacturers or importers) should be able to trace that component to its original component manufacturer.

认证方(国内生产商或进口商)应可以追溯到部件的最初生产商。

youdao