【填句补文】Some 20，000 tons of antibiotics are used in the European Union and the US each year. More than half are give to farm－animals to prevent disease and promote growth. ________.
A
The warning comes from a researcher in Switzerland who looked at levels of the drugs in farm slurry.
B
The drugs could be getting into our food and water.
C
Many drugs given to humans are also excreted unchanged.
D
But recent research has found a direct link between the increased use of these farmyard drugs and the appearance of antibiotic－resistant bugs that infect people.
