What the second duty is no one has yet discovered.

至于第二要务是什么，还没有人发现。

youdao

The problem with flip-flop controls is that they fail to fulfill the second duty of every control—to inform users of their current state.

滚翻控件的问题在于其无法完成控件的第2个职责——告诉使用者它们当前的状态。

youdao

U.S.Army Sergeant Jeremy Tormala, on his second tour of duty in Iraq, thought the elections gave a good indication that Iraqi forces will be up to the task.

VOA: standard.2010.03.08

There is one military aid on duty every second of every day including overnight.

所以每天每秒钟,包括整一个晚上,都有一个军事助理值班。

普林斯顿公开课 - 国际座谈会课程节选

Mr. MORRIS: Mark Vecchione was six months away from completing his second tour of duty in Iraq.

NPR: Cape Cod Soldier Dies in Iraq

He kept it alive and now that young man is serving his second tour of duty in Afghanistan.

CNN: Sunday comics plan unique 9/11 tribute

They will be heading back to Iraq for a second tour of duty.

NPR: Veteran Soldiers, Guardsmen Cut Careers Short