music: 60's Chart Toppers: Name The Artist: Ain't No Mountain High Enough?

Questions

who did "i'd love to change the world" in 1971?

what swimmer broke 50 records and then became a famous actor?

what do you call the hollow spaces in the bones surrounding your nose?

what word may be used to refer to a group of gnats?

what's a 10-20 to a police officer?