But some large groups say that US tax rules are a more important barrier.

但一些大型集团表示，美国的税收法规是更重要的障碍。

youdao

Carbon tax Australia will introduce a tax on carbon dioxide emissions from 1 July 2012, after the legislation passed its final barrier - approval by the Senate - on 8 November.

烟尘排放税11月8日立法通过最后一道关卡——议院批准，澳大利亚将在2012年7月1日增设二氧化碳排放税。

youdao

Responding for the government, Health Minister Earl Howe agreed that the present tax arrangements are "one potential barrier" to third-sector provision of health services.

BBC: Government defeated over VAT review for health charities

The pervasive complexity level of our tax system creates a barrier for taxpayers, wealthy or not, in their annual self-assessment attempt to arrive at a substantially correct determination of their tax.

FORBES: Tax Complexity, Confusion And Compliance