文章較難，大家聽(tīng)寫(xiě)填空即可~
Declining frog populations are considered an indicator of environmental damage. But new research finds that frogs might be doing even worse than we thought. Because the volunteers who count frogs by their sounds may be overestimating.
The North American Amphibian Monitoring Program is the country's largest frog-counting system. Volunteers listen for frogs, identify the species, and give population estimates. They've been doing this for over a decade.
Ted Simons from North Carolina State University and colleagues put recordings of frogs, like this wood frog, [Wood Frog sound] ____1____ to test the volunteers. They call it Ribbit Radio.
Many volunteers ____2____ false positives - they named frog species whose calls weren't being played. So there may be fewer frogs, or ____3____, than the surveys suggest. The results appear in the journal Ecology.
Simons is working with the U.S. Geological Survey - ____4____ the amphibian monitoring - to account for these false positives, and to better train the volunteers - so they don't write down "chorus frog" [Chorus Frog sound] when all there really was were pickerel frogs. [Pickerel Frog sound] ____5____.