In this section, you will hear several news items.
Listen to them carefully and then answer the questions that
follow.
Questions 21 to 23 are based on the
following news. At the end of the news item, you will be given 15 seconds to
answer the questions. Now, listen to the
news.
What is the definition of a tornado warning
A．The formation of a funnel cloud. B．The sighting of a funnel cloud. C．The bulletin issued by the National Weather Service. D．The convergence of favorable conditions for a funnel cloud to form.