Why is there no train from Hefei to Beijing Green Skin?

Train upgrade. The green leather car is an old train, and it is slow without air conditioning. There is no green leather car from Hefei to Beijing because the train has been upgraded. The old train has been running for a certain number of years and has been eliminated. It's all air-conditioned cars now. A train, also known as a railway train, refers to a vehicle running on the railway track, which is usually composed of multiple carriages and is one of the important means of transportation for human modernization.