Many different types of non-tariff barriers have been used, but the best-known of these are quota systems.
还有很多不同类型的非关税壁垒也一直在使用，广为人知的莫过于配额制度。
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However, we believe asubstantial amount of sales in 2011 will still be made to non-first-time buyerswho purchase new cars to replace their old vehicles, which sales are notsubject to the quota.