Task: Question Generation
Input (English): Now with NATO support in the form of air cover, the rebel militia pushed westward, defeating loyalist armies and securing control of the centre of the country. Gaining the support of Amazigh (Berber) communities of the Nafusa Mountains, who had long been persecuted as non-Arabic speakers under Gaddafi, the NTC armies surrounded Gaddafi loyalists in several key areas of western Libya. In August, the rebels seized Zliten and Tripoli, ending the last vestiges of Gaddafist power. On 25 August, the Arab League recognised the NTC to be "the legitimate representative of the Libyan state", on which basis Libya would resume its membership in the League.
Output (English): What organization provided air support to the Libyan rebels?