- 在研究植物光合作用产物的实验中，把天竺葵放到黑暗处一昼夜的目的是()
- 下列能正确表示光合作用的公式是()
- 绿色开花植物的植物体的构成是()
- 植物细胞同动物细胞相比，动物细胞没有的结构是()
- 控制物质进出细胞的结构是()
- 人体和其他动物以及绿色开花植物一样，结构和功能的的基本单位是：()
- 下列不属于生命现象的是()
- 阅读下面短文，掌握大意，然后从每题所给的A、B、C、D四个选项中选出最佳选项。Once, there was a beautiful girl who didn ’t like herself, because she was blind, she couldn ’t see anything. In fact, the girl __11__ nobody except her boyfriend, for he was always __12__ to help her. She used to tell her boyfriend, “ __13__ I could see the world, I would marry you. ” One day, someone donated* a pair of __14__ to the girl. When the bandages* came off ，she was able to see __15__ ,including her boyfriend for the __16__ time. He asked her, “Now that you can see the world, will you __17__ me?” The girl looked at her boyfriend and was greatly surprised to see that he was blind, __18__ . She had never expected that, and she would not like to be with a blind husband for the rest of her li fe, so she __19__ to marry him. Her boyfriend left in tears and a few days later wrote a __20__ to her, saying, “My dear, take good care of your eyes. Before they are yours, they were __21__ .” So, this is how the human brain* often works when our status* changes. Only a very few remember __22__ life was like before. And we often ask for more than we need. Life is a gift. Today, before you complain about the __23__ of your food ，think of those who have nothing to __24__. Before you complain about life ，think of some ones who went to heaven* too early. Before you complain about your old __25__ , think of the people who are living in the streets. And when you are ti red and complain about your job, think of those who have no jobs. In a word, enjoy the things you have and don ’t forget your past.
- 以下不属于威胁生物多样性的原因是()
- 下列关于染色体的叙述中，不正确的是()
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