Monarch butterflies, the large origin black insects, are common summer sights in northern United States and Canada.
出自-2014年6月听力原文
What makes monarch butterflies particularly interesting is they migrate, all the way to California or Mexico in back
出自-2014年6月听力原文
Every year in the late summer, monarch begin their migration to the south, those heading for Mexico go first for the Louisiana Mississippi region.
出自-2014年6月听力原文