[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.
-difference in quality 品质上的差异
There is a big difference in quality between the trial order and the order of this time.
-guarantee of quality 品质保证
We request a guarantee of quality for a period of one year on all the goods you sell.
-sacrifice quality 降低品质
If you sacrifice the quality and deliver goods of imperfect quality to us, well will refuse acceptance of them.