列车制动软管补助管的长度是() A. 1111MicrosoftInternetExplorer402DocumentNotSpecified7.8 磅Normal0 200~250 B. 1111MicrosoftInternetExplorer402DocumentNotSpecified7.8 磅Normal0 200~300 C. 1111MicrosoftInternetExplorer402DocumentNotSpecified7.8 磅Normal0 250~300 D. 1111MicrosoftInternetExplorer402DocumentNotSpecified7.8 磅Normal0 250~350