Today is my on duty for the day.

Today is my on duty for the day. Today is my turn for the morning traffic duty . Today is my t___ for the moring traiffic duty today is on my duty.thank you for you,i will try my best to is on duty today what is on duty today? who is on duty today Who is on duty today?为什么用on duty Who is on duty today ?是什么意思 谢谢 whose turn is it ( ) on duty today who is on duty today怎么回答 today is my on duty .I help my teacher ( ) many things.A.in