Please excuse me _______ your letter by mistake.
_______is no good always complaining about life. At least, we are living.
Helen listened carefully _________ she might discover exactly what John wanted.
Smoking, which may be _______ for some people, can cause great ______ to our health.
The role that our army_____ in flood control is very important.
I was very______ for him because he helped me out of trouble.