一、校学生会组建了关注树木成长联盟，积极宣传相关知识。阅读下面短文，了解一颗种子如何长成参天大树的吧！
（2025·南京市秦淮区期末改编）Did you take part in any tree - planting activities this past March 12? Or maybe you went to check out the little tree you planted a few years ago? Standing beside it，you might have been amazed at how much it has changed. It’s really great to watch a tree grow year by year. Even the tallest ones of them grow from tiny seeds. Have you ever wondered how?
A full - grown tree may drop hundreds or even thousands of seeds（种子）a year. Inside each seed is something called embryo（胚）. Think of it as a small group of cells（细胞）. These cells are ready to form roots，stem（茎），and first leaves.
Once the covering around the seed gets wet，the embryo cells，which have been patiently waiting，suddenly come to life. They start to grow and break out. This is called germination. First，the roots develop and push out and down into the soil. This makes sure the new plant can get water from the soil. Then the stem grows up and makes the first leaves. As these leaves produce “food” in the sunlight，the plant gets the energy to grow more new leaves.
Let’s imagine you drive a nail（钉子）into a tree at one metre above the ground. What will you see when you come back in ten years? The tree will be much taller，but the nail will still be only one metre above the ground. That’s because trees get taller by growing upwards from the top. At the same time，their trunk gets thicker by growing outwards. It is like the tree has two different ways of growing at the same time.
As trees get older，they continue to grow taller and thicker. Guess how tall the world’s tallest living tree is? Over 110 metres! That’s as tall as a 30 - floor building! Isn’t it amazing?
1. Why does the writer use the example of driving a nail into a tree in Paragraph 4?
A. To explain why people put nails in trees.
B. To help readers understand how trees grow taller.
C. To show that nails don’t stop trees from growing.
D. To teach readers a way to record the growth of trees.
2. 新考法 图片选择 Which one of the pictures shows the stage of germination?

3. 新考法 篇章结构 Which of the following best represents the structure of the passage?
A. Tell stories→List facts→Give a warning
B. Ask questions→Explain steps→Share a fact
C. List problems→Study reasons→Offer advice
D. Share experiences→Show examples→Introduce features