The Long Journey of the Monarch
帝王斑蝶的漫長旅程
— English reading, TOEFL
文章
Every autumn, millions of monarch butterflies leave Canada and the northern United States and fly south to central Mexico. Some travel more than four thousand kilometers.
每年秋天，數百萬隻帝王斑蝶離開加拿大和美國北部，向南飛到墨西哥中部。有些飛行超過四千公里。
What makes this journey remarkable is that no single butterfly has made it before. The monarchs that fly south are the great-grandchildren of those that left Mexico the previous spring.
這趟旅程令人驚奇之處在於：沒有一隻蝴蝶曾經飛過這條路。往南飛的帝王斑蝶，是前一年春天離開墨西哥那批蝴蝶的曾孫輩。
Scientists believe the butterflies use the position of the sun to find their direction. An internal clock lets them adjust for the sun's movement across the sky.
科學家認為，蝴蝶是靠太陽的位置來辨別方向。體內的生理時鐘讓牠們能依太陽在天空中的移動來調整。
In recent decades, their numbers have fallen sharply, mainly because the milkweed plants their young depend on are disappearing.
近幾十年來，牠們的數量大幅減少，主要是因為幼蟲賴以為生的馬利筋植物正在消失。
生詞
remarkable 非凡的
great-grandchild 曾孫
previous 先前的
position 位置
internal 內部的
adjust 調整
decade 十年
depend on 依賴