我们需要一封你上级的推荐信。

We will need a letter of recommendation from one of your ___superiors.

我们的上级总是帮助维持一个健康舒适的工作环境，这样我们工作更有效率。

Our ___superiors are always helping to maintain a healthy and comfortable work environment so we do our job more efficiently.

她在做最终决定前咨询了她的上级。

She consulted her ___superior before making the final decision.