题目

A research paper recently reported that the Chinese paddlefish (中华鲟) — one of the world’s largest freshwater fish — has been declared extinct.Scientists say the Chinese paddlefish and its close relatives have been around for at least 200 million years. The species, reaching up to seven meters in length, survived unimaginable changes, such as the mass extinction that killed the dinosaurs. But there’s one phenomenon this ancient species, sometimes called the “panda of the Yangtze”, could not survive humans.Their huge size and plentiful flesh made them a popular target for fishe②③线段的高点图上相距3厘米，两地的实地距离为（　　） A、1 500米B、3 000米C、4 500米D、6 000米