Now scientists have found in the past few years _________.

A．Professional killers should not be treated with humane treatment.
B．The violent robbers should think twice before pulling the trigger.
C．We should give the poisoner time to ponder about while he is shaking up or serving his arsenic cocktail.
D．Severe punishment, even death penalty, should be given to criminals.

A．man has overthrown Newton's laws of physics
B．man has solved a new set of gigantic puzzles
C．man has lost many scientific discoveries
D．man has given up some of the once accepted theories