In this section, you will hear several passages. Listen to the passages
carefully and then answer the questions that follow.
Questions 11 to 13 are based on the
following passage. At the end of the passage, you will be give 15 seconds to
answer the questions. Now, listen to the
passage.
What does "a black out" mean
A．People sometimes say they are in good health. B．The date of a major tragedy is remembered as a black out. C．A reduction in electric power. D．Officials order all lights turned off to make it difficult for enemy to find a target.