TOKYO (AP) — Mechanical hands dexterous enough to thread a needle, childlike dancing robots and adult-sized ones to help with deliveries were on display Thursday as the Humanoids Summit Tokyo opened. Among the dozens of companies taking part, including well-known players like Boston Dynamics and Toyota Motor Corp ., the big stars now were clearly the Chinese . Chinese newcomers, like Booster Robotics and LimX Dynamics, took the technology initially developed in Japan and the U.S. and fine-tuned