The world's animal populations（種群）have a reduced by more than two thirds since 1970，according to recent research from the World Wildlife Fund（WWF）.
    The London group provided information on 32，000 wildlife populations which included more than 5，000 species.The researchers（研究人員）found that group sizes had gone down by 69 percent in average（平均）.They said the loss of forests，human development of the environment，pollution，and climate change were great causes of the loss.Land-use change is still the most dangerous to wildlife.However，the researchers added，"If we cannot limit warming to 1.5℃，climate change was likely to become the main cause of biodiversity loss in the coming years.
    Wildlife populations in Latin American and the Caribbean Sea area were greatly influenced.The study showed a 94 percent drop in those areas in over 50 years.Wildlife populations in river and lake habitats（棲息地）went down the most.Freshwater populations have gone down by an average of 83 percent since 1970.For example，one population of pink river dolphins in the Amazon River area of Brazil fell by 65 percent between 1994 and 2016.
    The findings are a warning of a larger system problem.If the number of one species（物種）goes down，there will be a bad influence on ojye.airs.The situation will make the ecosystem（生態(tài)系統(tǒng)）worse.Humans depend on a proper climate，suitable weather conditions，better farmland and fisheries（漁業(yè)）to develop.However，now the problems are serious enough to threaten（威脅）many systems to last normally.
    Our future depends on preventing the loss of nature，just as it depends on the climate change.Everyone，from oneself to companies and to governments，should play an important role to improve the situation.If nothing is done，the numbers of the wild animals will be smaller and even none left.And at last，the problem will threaten the ecosystems on which we depend.

（1）What is the most dangerous to wildlife populations now？

Land-use change.

Land-use change.

（2）Why will the ecosystem be worse？

Because the number of one species goes down.

Because the number of one species goes down.

（3）What does the writer tell us to do according to the passage？

Everyone，from oneself to companies and to governments，should take action to improve the situation.

Everyone，from oneself to companies and to governments，should take action to improve the situation.

（4）How does the writer explain the falling of freshwater wildlife ？

By listing numbers.

By listing numbers.

（5）What should we do since the environment will make the ecosystem worse？ （請自擬一句話作答）

We should do what we can to protect the environment，for example ，stop fishing.

We should do what we can to protect the environment，for example ，stop fishing.