Over the years, China’ s railway network and high-speed railway are in the fast track of development. Being fast, _________, safe and steady, comfortable, China’s high-speed railways rank the leading place globally.  这些年来，中国的铁路网和高速铁路都进入了快速发展的轨道。 中国高铁速度快，_________，安全，平稳，舒适，居世界前列。
A、stable 稳定
B、punctual准点
C、inconvenient 不便捷