The development of industry has been ____gradual process throughout _____ human existence, from stone tools to modern technology.
The lady said she would buy a gift for her daughter with the ________.
_______ in 1636, Harvard is one of the most famous universities in the United States.
_______ time, he’ll make a first-class tennis player.
Remember _______ off the light when _______ to bed.
Stop _______ me to hurry up. I can only go so fast.