China's A.I. Advances Help Its Tech Industry, and State Security

During President Trump's visit to Beijing, he appeared on screen for a special address at a tech conference. First he spoke in English. Then he switched to Mandarin Chinese. Mr. Trump doesn't speak Chinese. The video was a publicity stunt, designed to show off the voice capabilities of iFlyTek, a Chinese artificial intelligence company with both innovative technology and troubling ties to Chinese state security.