the size of their roots the shape of their leaves the color of their flowers the structure of their cells
I gave my students this multiple choice question: Some different types of plants have characteristics in common. Which characteristic do most plants share?

Only one answer is correct among these 4 choices:
- the size of their roots
- the shape of their leaves
- the color of their flowers
- the structure of their cells

Could you tell me which one is correct?

the structure of their cells