A、The lack of clues about the species. B、Inadequate funding for research. C、Endless fighting in the region. D、The hazards from t

Lions have disappeared from much of Africa, but for the past few years scientists have wondered if the big cats were hanging on in remote parts of Sudan and Ethiopia. (5) Continuous fighting in the region has made surveys difficult. (6) But scientists released a report Monday documenting, with hard evidence, the discovery of "lost lions." A team with Oxford University’s Wildlife Conservation Research Unit, supported by a charity organization, spent two nights in November camping in a national park in northwest Ethiopia, on the Ethiopia-Sudan border. (7) The researchers set out six camera traps, capturing images of lions, and they identified lion tracks. The scientists concluded that lions are also likely to live in a neighboring national park across the border in Sudan. The International Union for Conservation of Nature had previously considered the area a "possible range" for the species, and local people had reported seeing lions in the area, but no one presented convincing evidence.
Questions 5 to 7 are based on the news report you have just heard.
5. What has made it difficult to survey lions in remote parts of Sudan and Ethiopia?
6. What was the main purpose of the research?
7. What did the researchers find in the national park?