原题
录音 1
According to the speaker, what did researchers know about monarch butterfly migrations before the new devices were developed?
AThe habitats monarch butterflies rely on during migration
BThe effects of climate on the success of monarch butterfly migrations
CThe stopover sites along monarch butterfly migration routes
DThe starting and ending points of monarch butterfly migrations
正确答案：D
解题思路
老师暂未填写解题思路。