三个小队共植树210棵，第一小队植了总数的 $\frac{2}{5}$ ，第二小队与第三小队植树的比为2：5，这三个小队各植树多少棵？

下面的形状分别是谁看到的？

已知各项均为正数的等比数列{}中，=5，=10，则=(    )

选词填写    Thomas Edison was a great American inventor（发明家）. When he was a child, he was always ____ questions and trying out new ideas. No matter how hard it was, he never gave up.
    Young Tom was in school for only three months. His teacher didn't understand why he had ____ many strange questions. Most of them were not about his lessons. The teacher didn't want to teach Tom any ____ . He asked Tom's mother to take the boy home. Tom's mother____ him to read and write, and she found him be a very good pupil. He learnt very fast and became very ____ in science.

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