---Mary was being badly treated when John happened to pass by and helped her out ---I think it was not a pure______but had been well planned.
22.______ in natural gas and oil, so this area is worth developing.
21.Here’s one of the best ways to protect your skin—_____ too much sunshine.
20.There used__________a post office at the corner of the street.
19.It is ________ who ____________ wrong.
18. He urged us to _____ this splendid opportunity to develop our movie industry.