定销的英文：
a system of fixed quotas for marketing

参考例句：

dowel pin
固定销

To guarantee the quality of our products, our factory makes quota system for producing, purchasing and marketing.
为确保产品质量，本厂实行定产、定购、定销制度。

system是什么意思：
n. 体系，系统；设备；制度；方法；身体；次序

Is the system unstable?
是系统不稳定吗？

It was not a perfect system.
它不是一个完美的系统。

This is a sexpartite system.
这是一个由六部分组成的系统。

fixed是什么意思：
adj. 固定的，不变的；（表情）呆滞的

Have you fixed on the date?
日期选定了吗?

The horse race was a fix.
这场赛马有人操纵。

Can you get a fix on the submarine?
你能给潜水艇定位吗?

quotas是什么意思：
n. 配额；定额；最低票数

"Quota, quotas... I have had it. "
配额，配额……我受够了。

The quota on luxury item have is revoke.
奢侈品限额已被撤消。

The production group has overfulfilled the quota today.
今天，这个生产小组超额完成了定额。