Recently the newspapers have reported several __________ of the coal mines happening in different provinces in China and the government has taken effective measures to stop such things.

When a space shuttle has accomplished its _____, it can be ready for another trip in about two weeks.

There being no witness on the spot, the police were delayed by the _____ of information about the crime.

I can’t say which sofa looks better. It’s just a (an) _____ of personal preference.

─Does this novel give you good     for your money?─I think so.