Definition: a group into which goods, services or people are put according to their standard Level: A2
你可以通过一等邮件更快地寄信。
You can send letters by first ___class mail for quicker delivery.
在长途飞行中，我更喜欢使用商务舱机票。
I prefer to travel with a business ___class ticket on long flights.
超市保证所有产品都是甲级质量。
The supermarket guarantees that all its products are ___Class A quality.
