商品品质决定交易本质上的价值，因此它是最重要的交易因素之一。
    贸易上的品质决定方法有：凭样品买卖，凭标准买卖，凭规格买卖等。下面我们来看看品质的表达发。

    [品质优良]：quality is excellent/ superior/ very good/ fine/ best/ high/ wonderful/ supreme/ attractive

    [品质低劣]：quality is bad/ inferior/ not good/ poor/ imperfect/ defective/ faulty/ second-rate/ lower/ unsatisfactory

    [品质保证]：retain the good quality; keep up to the standard quality; obtain a good quality; attain the best quality; secure an excellent quality

    [物品以达标准品质]：An article is up to the standard quality; An article is of the same quality as the standard; An article is equal to the standard quality; An article is the same as the standard quality

    [物品在标准以下]：An article is below the standard

    [物品在标准以上]：An article is above the standard

    [物品和样品一致]：An article is up to the sample; An article corresponds with the sample; An article is equal to the sample.

    -average quality 标准品质

    We would like to buy 500 tons of average quality corn.

    -customary quality 一般品质

    The quality of the goods shipped is customary quality.

    -best quality, prime quality, first-rate quality 最佳品质

    The goods supplied shall only be those of best quality.

    -quality inspection certificate 品质检验证书

    Please be sure to attach a quality inspection certificate.

    If you sacrifice the quality and deliver goods of imperfect quality to us, well will refuse acceptance of them.