___________

A．An increase in the ecotourism industry.

B．An increase in the use of land to raise crops and cattle.

C．A decrease in relative studies about their protection.

D．A decrease in the distance traveled during migration.

查看答案及解析进入在线模考

参考答案

答案解析

【预测】选项中重复出现的an increase和a decrease表明，本题可能考查造成某种后果的原因，可能涉及某种因素的变化。
【解析】B。录音中教授提到，随着人类在蜂鸟迁徙路线上的自然栖息地进行开发，扩建住房或是耕作或是放牧，蜂鸟在迁徙时能找到的食物变得更少，它们的筑巢区也会受到影响。B符合以上所述内容，故为答案。

你可能感兴趣的试题

1 ___________

A．They have built a series of hummingbird feeding stations.

B．They have supported new laws that punish polluters of wildlife habitats.

C．They have replanted native flowers in once polluted areas.

D．They have learned to identify various hummingbird species.

查看解析在线模考

2 ___________

A．Receiving radio signals from electronic tracking devices.

B．Being contacted by people who recapture banded birds.

C．Counting the birds that return to the same region every year.

D．Comparing old and young birds' migration routes.

查看解析在线模考

3 Questions are based on the recording you have just heard.
___________

A．The rocks cannot move after ice storms.

B．The rocks do not move at night.

C．The rocks never move in circles.

D．The rocks are not moved by people.

查看解析在线模考