Questions 14 to 17 are based on the
following passage. At the end of the passage, you will be given 20 seconds to
answer the questions. Now listen to the
passage.
What is the concern of ordinary people about the greenhouse effect
A．Whether it can be detected and checked. B．Whether it will lead to widespread food shortage. C．Whether global warming will speed up in the future. D．Whether it will affect their own lives.