We need a (n) _______ team leader who can really motivate the members to work harder.

—Oh, doctor, The wound on my leg is infected.  —You really shouldn’t have left it _______ to the sun. 

The task is very difficult. I wonder whether we will be able to finish it in the ________ of any other helpers.

The teacher ________ his work.

 Teachers words and deeds always _______ a great effect _____their students.