Two primary standard reference fuels, normal heptane and iso-octane arbitrarily assigned 0 and 100 octane number, respectively, are then blended to produce the same knock intensity as the test sample.

两种基准参考燃料正庚烷和异辛烷分别被定义成辛烷值为0和辛烷值为100，将它们混合产生与实验样本相等敲缸强度的爆震。

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The meaning of a word can be derived from its etymology or it can be assigned arbitrarily and artificially.

FORBES: American Political Economy Is No Different From English Language