问题
选择题
制作临时玻片标本时夹取的生物材料要（ ）
A．薄而透明
B．完整的
C．要新鲜
D．以上都可以
答案
显微镜是利用光学原理成像的，观察的材料必须是薄而透明的，光线能透过，才能观察清楚．即反射的光线要透过观察的材料进入人眼才能看清物像；若不透明，光线就不能通过观察的材料经物镜、目镜进入眼内，在视网膜上形成物像成像，就看不清物像了．
故选A
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制作临时玻片标本时夹取的生物材料要（ ）
A．薄而透明
B．完整的
C．要新鲜
D．以上都可以
显微镜是利用光学原理成像的，观察的材料必须是薄而透明的，光线能透过，才能观察清楚．即反射的光线要透过观察的材料进入人眼才能看清物像；若不透明，光线就不能通过观察的材料经物镜、目镜进入眼内，在视网膜上形成物像成像，就看不清物像了．
故选A
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| One girl left her home after a quarrel (争吵) with her mother. She walked for a long time. Then she saw a noodle shop. She was 1 , but she didn't have any money with her. The shop owner was 2 old granny. She asked her,"Do you want 3 a bowl of noodles?" "But I have 4 money." Said the girl. "Don't worry." Soon, the granny 5 the girl a bowl of noodles. The girl ate for a while and started to 6 . "What is the matter?" the granny asked. "I am just 7 deeply! You are so kind. We don't know 8 but you cooked noodles for me. But my own mother, after a quarrel, sent me out of the house." " 9 can you think that way? I just cooked you a bowl of noodles. Your mother cooks for you every day. Why don't you say 10 to her?" The girl was surprised and went home at once. Her mom was waiting her for supper. The girl's eyes are filled with tears again. | ||||
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