What does the rolling development of China Railway Construction 131 project mean?

the rolling development has achieved remarkable results. As of December 9, 222, the rolling development of China Railway Construction 131 Project means that the rolling development has achieved remarkable results. China Railway Construction Group Co., Ltd., formerly known as the Chinese People's Liberation Army Railway Corps, is now a super-large comprehensive construction group managed by the State-owned Assets Supervision and Administration Commission of the State Council.