Everybody has ______ to play _____ our environment.
________ a man's age, he can reduce it several years by wearing a confident smile.
After a year, doctors diagnosed him with a disease so rare ________ it affects just one in 8 million children.
________ you need something, please don't hesitate to let me know.
One more week, ________ we will accomplish the task better.
He never thought that his success came ________ he least wanted it.