摘要
Experiments using miniature 2 treadmills 3 have revealed how an Arctic-dwelling bird is superbly 4 adapted for 5 life in extreme conditions. The rock ptarmigan——a chicken-like bird that lives year-round on the Arctic ice and tundra 6——is just as fit when it has fattened up 7 for the winter. The birds, also known as snow chickens,
Experiments using miniature 2 treadmills 3 have revealed how an Arctic-dwelling bird is superbly 4 adapted for 5 life in extreme conditions. The rock ptarmigan--a chicken-like bird that lives year-round on the Arctic ice and tundra 6--is just as fit when it has fattened up 7 for the winter. The birds, also known as snow chickens,
出处
《大学英语》
2012年第11期38-39,共2页
College English
