243.Store managers are often the last to hear complaints, and often find out only when their regular customers decide to frequent their competitors, according to a study jointly conducted by Verde Group and Wharton School.

英语四级译文:
由维德集团和沃顿商学院共同进行的一项研究表明，店面经理通常是最后听到投诉的人，而且通常只有在他们的老主顾决定时常光顾他们竞争对手的店铺时才发觉。

四级词汇讲解:
本句的主干是managers are the last to hear complaints, and find out o and连接的是并列的谓语部分are often…和often find out...;when引导的是时间状语从句;according to…为整句的状语，其中jointly conducted by…为study的后置定语。

find out的意思是“获知，发现”。如:
How did you find out what time the train leaves?你是怎么查出火车什么时候开车的?

frequent此处为动词，意思是“常去，常到”。如:
He used to frequent bars and clubs.他过去常去酒吧和俱乐部。

according to的意思是“根据，依照”。如:
Everything went according to plan.一切都按计划进行。

英语四级考点归纳:
last作名词时，常见短语如下:

※ the last of意为“最后的，最后提到的”。如:
These are the last of our peaches.我们就剩下这些桃子了。

※ at (long) last意为“经过努力、延误等，终于”。如:
At last we are home!我们终于到家了!

※ to/till the last意为“坚持到底，直到最后一刻”。如:
He died protesting his innocence to the last.他至死都坚称自己无罪。