A、The distance that a food product travels to a market from its source area. B、The distance between UK and other food producing

An environmental group called the Food Commission is unhappy and disappointed because of the sale of bottled water from Japan. The water, angrily argued in public, has traveled 10,000 "food miles" before it reaches Western customers. "Transporting water halfway across the world is surely the extremely stupid use of fuel when there is plenty of water in the UK." It is also worried that we are wasting our fuel by buying prams from Indonesia(7,000 food miles)and carrots from South Africa(5,900 food miles).     Counting the number of miles traveled by a product is a strange way of trying to tell the true situation of the environmental damage done by an industry. Most food is transported around the world on container ships that are extremely energy efficient. It should be noted that a ton of butter transported 25 miles in a truck to a farmers’ market does not necessarily use less fuel on its journey than a similar product transported hundreds of miles by sea. Besides, the idea of "miles" ignores the amount of fuel used in the production. It is possible to cut down your food miles by buying tomatoes grown in Britain rather than those grown in Ghana: the difference is that the British ones will have been raised in heated greenhouses and the Ghanaian ones in the open sun.
    What the idea of "food miles" does provide, however, is the chance to cut out Third World Countries from First World food markets. The number of miles traveled by our food should, as I see it, be regarded as a sign of the success of the global trade system, not a sign of damage to the environment.
Questions 16 to 19 are based on the passage you have just heard.
16. Why is the Food Commission angry?
17. What does the phrase "food miles" mean according to the passage?
18. What does the speaker try to explain by comparing tomatoes raised in Britain and in Ghana?
19. Who is most probably giving this talk?