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。

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At best, certifiers may struggle to examine vast concessions on brief visits, as the guests of loggers who are also paying their fee.

ECONOMIST: Western consciences can do only so much to conserve forests