 Complete the following phrase:  The station logo represents the caduceus, a variant of the Rod of Aesculapius, the Greek god of medicine. Its name refers to the Centro Médico Siglo XXI general hospital, located above the metro station. The station opened along Line 3 on 7 June 1980 when Centro Médico served briefly as the southern terminus of that line. Line 3 service then extended further southward toward Zapata a year later by 25 August 1980. The Centro Médico Siglo XXI was almost destroyed by the 