In paragraph 4, the author states, “In the digital age, we’re seeing more sophisticated limbs.” What details does he provide in support of this main idea? "The most obvious bionics are those that replace limbs. Olympian “Blade Runner” Oscar Pistorius made a splash with his Cheetah carbon-fiber prostheses. Yet those are a relatively simple technology—a curved piece of slightly springy, super-strong material. In the digital age, we’re seeing more sophisticated limbs."