The 12 million people in Mexico City woke up on September 19th, 1985, to find their city ________ after the terrible quake.
Keep away from the dog , _______it will bite you.
He made up his mind to devote all he could _____ his spoken English before going to college.
We live in a society ______ there is a great deal of debate about competition.
The fact ____ ancient Greek civilization had a great influence on Western culture is known to many people.
---_______ the farmers discovered the entrance to the secret cave in the valley? --- Totally by chance.