---- I’m sorry I stepped outside for a smoke. I was very tired. ---- There is no _____ for this while you are on duty.

Many people complain of the rapid ________ of modern life.  

The UN Climate Change Conference in Copenhagen was held in a tense ______ due to lack of deep understanding.

To make members of a team perform better，the trainer first of all has to know their      and weaknesses．

The policeman saved the little girl from the gangs. He’s never afraid of them. I think he is a man of _________.