Andrew Su, CEO at brokerage Compass Global Markets said the average cost of producing gold in Australia, home to some of the world's biggest gold miners, has jumped from $500 an ounce in 2007 to over $1,000 an ounce this year.
Persons (plural) is a very formal word. We only use it in rather legalistic contexts: [notice in a lift] Any person or persons found in possession of illegal substances will be prosecuted.
The words everybody, and everyone are indefinite pronouns, and they are always singular. They should be used with his or her, but you could use their instead. Example 1: Everybody has his or her own problems. Example 2: Everybody has their own problems.