【康老师IBT阅读真经】鸟.doc

精選iBT熱門閱讀真經(零零四)：■ 三隻小鳥在樹上唱hip pop，猜一個字? （06.03.25、06.07.29、06.11.17、06.12.08） 分類：新托福真經 2007/02/20 09:05  ? ? ■? 鳥類遷徙：（06.03.25、06.07.29、06.11.17、06.12.08） 關於鳥類遷徙：由於鳥類遷徙時遇到陰天就停下來，好像分不請方向，所以科學家predict 鳥類遷徙靠太陽指引方向。做實驗，用artifical sun 取代 real sun，鳥依然朝artifical sun飛。科學家作試驗看食物是不是另外一種guide導致鳥類的遷徙。結果發現鳥類能否找到食物完全依賴光線，也就是視覺。也就是說食物不能促使鳥類遷徙。另外一個試驗又證明夜晚遷徙的鳥類靠star 來定位。另外一個在什麼天文館做的試驗又證明夜晚遷徙的鳥類靠star 來定位。後面是一個同類的實驗。但是鳥類在向著artifical sun 飛行時，每小時會變換方向15度角，而這也是真實的太陽方向變化的速度，估計是由鳥類自身生物鐘引起的。鳥的生物鐘直接與太陽光強弱有關，白天遷徙的鳥類根據在太陽光線的強弱飛行的距離，太陽下山前鳥類一定會準時到達其預定地點。附帶還記得考的單詞：prediction, core, offset... ? ? 在補充知識前，來考考同學好了， 三隻小鳥在樹上唱hip pop，請猜一中文個字???????? ? ? ? 答案最下面 ? (精選iBT熱門閱讀真經，取自：字神帝國2007新橘寶書新托福真經考前點題名師大講堂講義：以下機經皆同學們在網上分享，感謝這些好心的同學，編者只是將其整理，與大家分享，祝福大家有好成績的哦 ^ ^。) ? Animal migration ??????????? Humpback whales and blue whales make long migrations. They spend the summer in polar oceans, which have plentiful food. In the autumn, they swim toward the equator until they reach the warm tropical seas. There, the females that are pregnant give birth. ? Migration Birds Know No Boundaries ??????????? The migration of birds is one of the most fascinating and least understood events in nature. ??????????? Arctic terns are the champions of long-distance migration. They fly about 11,000 miles (17,700 kilometers) from their breeding grounds in the Arctic to their winter home in the Antarctic. ? ? ? ? Why birds migrate ??????????? In many parts of the world, the foods that birds eat become scarce during certain seasons of the year. Most birds would starve if they had to remain in such places through the unfavorable season. ??????????? Although birds migrate to survive, the factors that actually trigger their migrations are much more difficult to explain. For example, many northern species leave their summer home while the weather is still warm and the food supply plentiful. ??????????? Bird migrations are probably regulated by the glandular system. The glands produce chemical substances called hormones. ?????????