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

—Henry has been teaching English in Beijing university for many years.—It’s no __________ he can speak Chinese so well and idiomatically.

You’d better practice more and play better if you want to make a good ______ on the audience at the concerts.

It is a great______for a person to be able to drive when he is seeking a job.

Those bad conditions have given ______ to a lot of crime in the area.