迷你对话A: I will go on business next month on behalf of our boss.

我下个月代表老板出差。

B: Sounds good. Don’t let your boss down.

听起来不错哦！不要我们老板失望了。

地道表达let sb down1. 解词释义Down在英文的口语中表示“心情不好，心情低落”或者是“觉得失望”，它也有“沮丧”的意思，跟blue（忧郁）意思差不多。例如：Why are you feeling down?（你为何感觉心情不好？）或者是Why are you feeling blue.

2. 拓展例句e.g. I' ve trusted you all along the line and now you' ve let me down.

我一直信任你, 可是现在你却让我失望。

e.g. He let me down at the last minute and turned out to be a broken reed.

他在紧急关头拆了我的台，成了背信弃义的人。

e.g. He's in an agony of worry over the baby, and he feels she let him down.

他为了孩子而忧心如焚，而且他认为她误了他的大事。

e.g. He's laying his reputation on the line to help you.Don't let him down.

他冒着名誉受损害的风险助你一臂之力。不要辜负他的一片好心。

Ps ：on behalf of的意思是“代表......”。例如：

Secret Service officer Robin Thompson spoke on behalf of his colleagues.

特工处官员罗宾·汤普森代表他的同僚发表了讲话。

He spoke on behalf of all the members of the faculty and staff.

他代表全体教职员工讲了话。

Ps : go on business的意思是“出差”。例如：

I was ordered to go on business.

我奉命出差。

When we go on business tomorrow, we're going the same way.

明天出差, 咱俩是一路。