The world's animal population has decreased by 50% in the past 4 decades.
A、T
B、F
【正确答案】：A
【题目解析】：听力原文：The world's animal population has halved in 40 years as humans put unsustainable demands
on Earth, a new report warns. The World Wide Fund for Nature's Living Planet Index revealed the dramatic decline in animal species, and said the trend could cost the world billions in economic losses.本题考查对应数字。原文说一份新的报告警告说，由于人类对地球提出了不可持续的需求，世界动物数量在40年内减少了一半。题干说在过去的40年里，世界上的动物数量减少了50%。在40年内减少了一半和40年里减少了50%意义一致，所以正确。
