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Section Three: Reading Comprehension (3)

Jazz has been called “the art of expression set to music”, and “America’s great contribution to music”. It has functioned as popular art and enjoyed periods of fairly widespread public response, in the “jazz age” of the 1920s, in the “swing era” of the late 1930s and in the peak popularity of modern jazz in the late 1950s. The standard legend about Jazz is that it originated around the end of the 19th . | In the 1930s hundreds of hospitals used maggot therapy. Maggot therapy requires the right kind of larvae. Only the maggots of blowflies (a family that includes common bluebottles and greenbottles) will do the job; they devour dead tissue, whether in an open wound or in a corpse. Some other maggots, on the other hand, such as those of the screw-worm eat live tissue. They must be avoided. When blowfly eggs hatch in a patient’s wound, the maggots eat the dead flesh where gangrene-causing bacteria thrive. They also excrete compounds that are lethal to bacteria they don’t happen to swallow. Meanwhile, they ignore live flesh, and in fact, give it a gentle growth-stimulating massage simply by crawling over it. When they metamorphose into flies, they leave without a trace – although in the process, they might upset the hospital staff as they squirm around in a live patient. When sulfa drugs, the first antibiotics, emerged around the time of World War II, maggot therapy quickly faded into obscurity.