One of our main duties is to protect it.

我们的主要责任之一是保护它。

youdao

My main duties were to deal with customer complaints.

我的主要职责是处理客户投诉。

youdao

The main duties of forest guards are: patrol the forests and prevent forest resources from being destroyed.

护林员的主要职责是：巡护森林，制止破坏森林资源的行为。

youdao

Along with the peace-keeping force will be military observers, staff officers and civilian police and among its main duties will be assisting preparations for next year's elections.

BBC: NEWS | Africa | UN peace force for Ivory Coast

Creative incompetence will achieve the best results if you choose an area of incompetence which does not directly hinder you in carrying out the main duties of your present position.

ECONOMIST: Guru

We're still some distance away from once again hopping on Dreamliners for long-haul flights, but the aircraft will at least have a chance to flex their muscles before they resume their main duties.

ENGADGET