---Oh, doctor, the wound on my leg is infected.---You really shouldn’t have left it _______ to the sun.
______ I went to London, I was strongly impressed with the beautiful buildings.
What ______ me most was not what he told me but why he looked at me in _______ all the time.
It is because of a long ________ from school that I am a bit behind the other classmates.
No sooner ______ on board the train than it started to move.
—I think everyone has a role to play in making the planet a better place.—Yes, indeed. ______.