选C ∵L1平拦禅行L2∴△AFG∽△BFD∵行伍AF:FB=2:5∴AG:DB=2:5∵BC:CD=4:1∴CD:BD:AG=1:5:2∵L1平行L2∴△AEG∽△CED∵简带尘AG:CD=2:1∴AE:EC=2:1