Misc: what actor played the psychopath hitchhiker in the hitcher?

Questions

Some soft drinks are made sweeter by adding?

Albert Einstein was thought to be suffering from dyslexia, as he couldn't speak properly until he was _____ years old?

The Chinese used fingerprints as a method of identification as far back as AD?

Sir Isaac Newton was only _______ ______ years old when he discovered the law of universal gravitation?

A flush toilet exists that dates back to?