问题
选择题
将鲫鱼从水池中取出，不久鲫鱼便会死亡。这是鲫鱼的呼吸器官是（ ）
A．鳃
B．肺
C．气管
D．湿润的皮肤
答案
答案：A
题目分析：鱼类的呼吸器官是鳃，里面有大量的鳃丝，含有毛细血管，在水中，鳃丝展开，使水中的溶解氧进入血液，而血液中的二氧化碳进入水中，完成气体交换；鱼离开水后，鳃丝由于缺水，黏在了一起．导致鱼无法呼吸，最后窒息死亡．故选：A．
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将鲫鱼从水池中取出，不久鲫鱼便会死亡。这是鲫鱼的呼吸器官是（ ）
A．鳃
B．肺
C．气管
D．湿润的皮肤
答案：A
题目分析：鱼类的呼吸器官是鳃，里面有大量的鳃丝，含有毛细血管，在水中，鳃丝展开，使水中的溶解氧进入血液，而血液中的二氧化碳进入水中，完成气体交换；鱼离开水后，鳃丝由于缺水，黏在了一起．导致鱼无法呼吸，最后窒息死亡．故选：A．
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| Everyone needs friends. But do you know 1 to find real friendship (友谊) and keep it? An American writer 2 Sally tells young students some good ways to find 3 . Sally says finding friendship is just like 4 a tree. You plant the seed (种子) and 5 it to make it grow. She says you should first choose someone 6 can be a good friend. It doesn't matter whether he has money or good looks. A good friend should be kind and 7 . If you have a bad day, a good friend should 8 your complaints (抱怨) and do his 9 to help you. If you want to make a friend, you should make each other 10 . But things cannot always be happy. 11 the best friends may have quarrels. What should you do when you 12 with your friend? You may try to have an honest talk with him when there is no one around. If he 13 want to talk, you can write a letter to tell him how you are feeling. Sally also tells us some small but important things, 14 example, celebrating your friend's success. Remember that friendship is the 15 important thing in your life. Life is great if you have friends! | ||||
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