We're short-staffed at the moment.So I have to do all the designing,executing as well as marketing.
我们现在人手不足。所以我一个人要兼顾设计，执行和市场的工作。
Oh, We can't have you pulling the cart all by yourself.You will burn out.
哦，可不能让你一个人这么忙活，你会吃不消的。

Why do you bring Kenny back?You know we're archenemies.
你为什么把肯尼又请回来了？你知道我俩是宿敌。
Relax.We're a firm. We can't have you pulling the cart all by yourself all the time.
放松啦。咱们可是一个公司，不能让你一个人做所有的事情吧。

精讲部分

We can't have you do all the work.
We can't have you pulling the cart all by yourself.
pull the cart all by oneself字面意思为“独自一个人拉着手推车”，引申开来就是“自己一个人挑大梁，承担全部的责任”，即shoulder all the responsibilities by oneself,这是一个十分形象的比喻。那么“我们不能让你一人做所有工作”也就是:We can't have you pulling the cart all by yourself。