At the end of the passage the author seems to suggest that life in future is ______

A．Human beings didn't have sharp teeth like other meat-eating animals and tools helped them to get food more easily.
B．Tools helped to develop human intelligence.
C．Tools helped the human beings to cut meat and skin from dead animals.
D．It was easy to make stone tools.

A．Bosses create stress.
B．Workers don' t need bosses.
C．Workers should participate more in decision-making.
D．Workers know better than bosses.