History is littered with examples of people______ , tempering and then tumbling.

A. It is a bad idea.
B. It is as effective as speed bumps.
C. It is not useful.
D. It should be combined with education.

A. They follow traffic rules closely.
B. They keep within speed limits.
C. They like to go at high speed.
D. They tend to drive responsibly.

A. Make cars with automatic control.
B. Make cars with higher standards.
C. Make cars that are less powerful.
D. Make cars that have better brakes.