题目

鸟类呼吸时新鲜空气通过肺部的方向是（   ） A．吸气时新鲜空气从头方到尾方穿过肺，呼气时是从尾方到头方穿过肺 B．吸气和呼气时新鲜空气均从头方到尾方穿过肺 C．吸气和呼气时新鲜空气均从尾方到头方穿过肺 D．吸气时新鲜空气从头方到尾方穿过肺，呼气时是从尾方到头方不通过肺 答案：C 解析: 前年竞赛原题，鸟类具有独特的双重呼吸，在呼气和稀奇时均有前后气囊的参与，气流通过的方向为口——前气囊（位于身体后部）——肺及各级支气管——后气囊（位于身体前部）——口，所以答案为D，若还不明白可参照《普通动物学》（刘凌云）上的图解十一、阅读短文，根据短文内容判断正误，正确的打“V”，错误的打“X”。(10%) Linda is very sad. Her cat is in the tree. She calls it again and again,but it can't climb down. Now Peter comes. He asks Linda ,“What,s the matter?” Linda says ,“My cat is in the tree. It can't climb down."“Don,t worry. Let me help you."Says Peter. Then he climbs up the tree.The cat jumps down from the tree and runs away. Linda runs after her cat.But Peter doesn’t know how to climb down the tree,either. Now he is in the tree.() 1. Linda calls Peter again and again.() 2. Peter helps Linda to climb down the tree.() 3. Linda and her cat run away.() 4. Peter can't climb down the tree. .() 5. Linda helps Peter climb down the tree.