The project is so designed that once _______ nothing can be done to change it.
Having worked abroad for five years, he _________ much experience in dealing with international affairs.
Mrs. Jones does not like shopping, and ______ like gardening.
Polar bears live on sea ice, which they use as a platform for hunting seals.
______for the timely investment from the public, our company would not be so booming now.
—Was it two months ago__ you luckily got an opportunity to spend your holidays in Spain? —______. John was the lucky dog.