I am going to the post office. Do you have any letter _________?
-----Where was it________the road accident happened yesterday? -----In front of the market.
All ________is needed for life on board the submarine comes from the ocean.
Your pen________smoothly. Where did you buy it?
All of people in the world should enjoy equal treatment, ________race, religion or sex.
We forbid _____ in the reading room. That is, you are forbidden _____ in the reading room.