. Researchers developing prosthetic devices have recently discovered a way to _____. . cure populations of the HIV/AIDS virus . grow new brain cells in patients with post-traumatic stress syndrome . fuse patients’ nerves to robotic limbs . attach artificial limbs to the bodies of injured veterans . . 2. Who resigned the presidency of Egypt as a result of “Arab Spring” demonstrations? . Bashar al-Assad . Hosni Mubarak . Muammar Gaddafi . Mohamed Morsi . . 3. Compared with Americans, who spend little more than 15 percent of their income on food, people in less developed countr