双轨铁路

double track railway;duorail

• unidirection
• unidisciplinary
• unification church
• unified field theory
• uniform
• uniformitarianism
• uniformity，acts of
• unify
• unilateral
• uniline
• unilinear
• unilingual
• unilocal residence
• unimaginative
• unimodal
• unimpeachable
• unimproved
• unincorporated
• uninformed
• uninscribed
• uninsured
• unintelligence
• unintelligible
• unintended
• uninterchangeability