Based on the article, which of these is true about search-and-rescue dogs?
Scientists have learned that search-and-rescue dogs are more reliable on television than in real life.
Search-and-rescue dogs are better at tracking scents than any human or any machine invented so far.
Search-and-rescue dogs have been trained to calculate the population sizes of endangered animals.
Scientists believe that search-and-rescue dogs may someday take the place of medical researchers.