BREMERTON, WA— A head of genetically modified broccoli shrieked its numerous benefits at shoppers Monday in a Seattle-area Safeway. "I contain 40 percent more vitamin A than non-modified broccoli!" the head screeched at terrified produce-aisle customers. "I can fight off insects and disease without the use of pesticides!" Monsanto, makers of the vegetable, stressed that genetic-modification technology is still in its infancy, and that more pleasantly voiced broccoli should hit store shelves by 2003.