Here's how miniliq did on the following questions:

18) In the winter of 1976, the three (3) airlines flying the DFW-ABQ route were: Continental with B727-200 service, Frontier with B737-200 service and Texas International with DC-9-10 service. In addition to their respective nonstop services, CO also operated one stop direct flights via either ELP or MAF while TI flew a two stop direct service via MAF and ROW. American and Southwest (which you referred to as "Southwestern") were not flying between DFW(AA)/DAL(WN) and ABQ at this time.

19) Correct! Ozark flew DFW-MKE nonstop with DC-9-30 equipment while Texas International operated nonstop with DC-9-10 aircraft. BTW, Midwest Express wasn't around yet.