词汇精讲：

1. superior

adj. 上级的；优秀的，出众的；高傲的
n. 上级，长官；优胜者，高手；长者

eg. We overwhelmed the enemy by superior forces.
我们以优势兵力打垮了敌军。

eg. When, and only when, these behaviors occur does an authority relationship exist between the superior and subordinate.
当且仅当这些行为发生时，在上级和下级之间才存在一种权威关系。

eg. A superior officer can deny a Purple Heart, but such denials usually require review and then concurrence by a General-level officer.
高级长官可以拒绝这种申请，不过需要将军级别的官员的重审和批准。

eg. I like working without interference from my superior, but I am able to be self-control and organise my job well.
我喜欢工作上没有直属长官的干扰，但是我能够自己约束自己，并且把工作组织的很好。

2. moderate

adj. 稳健的，温和的；适度的，中等的；有节制的
vi. 变缓和，变弱
vt. 节制；减轻

eg. The United States believes that a strong, moderate Taiwan is a force for stability, prosperity and democracy in the region.
美国认为，一个强大、稳健的台湾是该地区一支稳定、繁荣和民主的力量。

eg. Regular, moderate exercise such as swimming or walking can help relieve the day's stresses and strains.
定期，如游泳或散步可以帮助减轻一天的压力和紧张适度的运动。

eg. She should moderate her language when children are present.
在孩子面前，她说话应该节制。

3. sellable adj. 适于销售的

most sellable 最畅销的

best-seller 最畅销书

其他表达法：

By virtue of its super quality, this product is often sold out in many areas.
由于质量上乘，这款产品在很多地区经常脱销。

These items are the most sellable in our market.
这些商品在我方市场最为畅销。