On a scorching July afternoon in Shanghai, dozens of Chinese students hunch over tablet screens, engrossed in English, math and physics lessons. Algorithms track every keystroke, and the seconds spent pondering each question. A pair of teaching assistants linger quietly in the background, intervening only when necessary.For Derek Li, the 47-year-old founder of Chinese ed-tech company Squirrel Ai Learning, this is the future of education: adaptive software powered by artificial intelligence that’...