体细胞中含有3对同源染色体的生物，经减数分裂产生的配子，同时含有三个父方（或母方）染色体的配子占多少（  ）

    When I was in the ____ (九) grade, luckily, I was chosen to be the princess in the school play. For weeks my mother had helped me practice my lines. But ____ (一旦) on the stage, every word disappeared from my head. Then my teacher asked me to change my role to be a narrator (解说者) for the play.

    ____ (尽管) I didn't tell my mother what had happened that day, she noticed my unhappiness. She asked if I wanted to take a walk in the garden.

    It was a lovely spring day. We could see several dandelions (蒲公英) ____ (在…中间) the grass. I watched my mother bend down by one of the dandelions. "I think I'll dig up all these weeds (野草)," she said. "From now on, we'll only have roses in this garden."

    "But I like dandelions," I disagreed. "All flowers are beautiful-even dandelions!"

    My mother looked ____ (严肃地) at me. "Yes, every flower gives pleasure in its ____ (自己的) way, doesn't it?" she asked thoughtfully. I nodded. "And that is true of people, too," she added.

    When I ____(意识到) that she had guessed my pain, I started to cry and told her the ____ (真相). "But you will be a wonderful narrator," she said, reminding me of how much I loved to read stories aloud.

    Thanks to my mother's encouragement, I got to know everybody had his or her ____ (价值) in the world. I felt ____ (骄傲的) of the role in the play.

材料一：俄国1861年农奴制改革后，农民缴纳的巨额赎金为发展大工业增添了新的资金来源；获得解放的2000多万农民为大工厂提供了充足的自由劳动力；农村自然经济的进一步瓦解扩大了国内市场。

——摘编自《世界史》

材料二：1920年，三年国内战争结束。苏俄却遇到了巨大困难……人民生活困苦……第二次世界大战中，苏联为世界反法西斯战争做出重要贡献。

——摘编自《世界史》

材料三：1985年8月28日，邓小平在会见外宾时，曾说到“社会主义究竟是个什么样子，苏联搞了很多年，也并没有完全搞清楚。列宁的思路比较好……，但是后来苏联的模式僵化了。”

——《邓小平文选》

材料四：1933年，罗斯福就任美国总统。面对“大萧条”现状，他坚定地认为，这个国家需要进行大胆的、坚持不懈的试验，如果试验失败，就再试行另一种办法，最重要的是要进行试验。

——摘编自《世界史》