这些名词均有“级、等级”之意。
class : 含义广泛，指人或物按优劣划分的等级，也指学校中的年级或班级。
- Whenever I travel by train, I always travel first class.
我每次乘火车旅行都坐头等车厢。 - first/second class mail
一类／二类邮件 - a business/economy class ticket
商务舱／经济舱的机票 - When it comes to mathematics, he's in a different class to his peers.
说到数学，他和他的同龄人不在一个级别上。
degree : 指程度、范围不同，社会地位的高低。也可指形容词或副词的级。
- This job demands a high degree of skill.
这项工作对技术的要求很高。 - There isn't the slightest degree of doubt that he's innocent.
毫无疑问，他是无辜的。 - I have to warn you that there's a degree of (= some) danger involved in this.
我必须警告你这里面有一定的危险。 - The number of terrorist attacks has increased to a terrifying degree.
恐怖袭击的次数已经到了骇人的程度。 - There was some degree of truth in what she said.
她说的有一定的真实性。 - To what degree do you think we will be providing a better service?
你认为我们的服务还有多大的改进空间？ - "That's really bad." "Well, it's all a matter/question of degree (= there are other things better and other things worse)."
“那可真是太糟糕了。”“只是程度不同而已。”
grade : 指按地位或优劣划分的等级，既可指人又可指物。
- He's suffering from some kind of low-grade (= slight) infection, which he can't seem to get rid of.
他感染程度较轻，但好像就是无法痊愈。 - There's some really high-grade (= high quality) musicianship on this recording.
这张唱片体现出高超的音乐技能。 - Bill has been on the same grade (= his job has been of the same level of importance, or he has had the same level of pay) for several years now.
比尔在同一个职位上已经呆了好几年了。
rank : 指人在社会中的地位或等级，尤指军队中的军衔。
- senior/high/junior/low rank
高／低级职位 - He has just been promoted to the rank of captain.
他刚被提升为上尉。 - Ministers of cabinet rank receive a higher salary than other ministers.
进入内阁的部长比其他部长的工资高。 - Having a large income is one of the advantages of rank (= high position).
职位级别高的好处之一就是收入高。
