It is generally accepted that humans have an ability to learn language from the time of their birth.

A．The environment crisis will not be solved unless we stop using virgin materials.
B．In scientific research, a higher priority should be given to understanding all living systems.
C．Exploration of outer space will finally lead to an improvement on human living conditions.
D．S. high-technology companies are applauding this new twist in scientific research.

A．A growing number of Americans are doubtful about what high technology can do in solving the world's problems.
B．Many scientists are beginning to believe that the better understanding of human beings will play a more decisive role in solving the world's problems.
C．More and more young scientists are trying their best to find new ways to solve the world's problems.
D．Technological creativity will still play a very important part in solving the world's problems.