To determine the correct answers, we need to analyze how paragraphs 10-12 contribute to the development of ideas in the passage. Based on the options provided:
B. They explain how other species depend on big trees.
This statement likely captures an essential idea about the ecosystem and interdependence, which may be relevant to the big trees' importance.
E. They show how some big trees are more important than others.
This statement suggests a nuanced view of the significance of different big trees, which could be a critical aspect of understanding the value of biodiversity and conservation efforts.
Therefore, the TWO statements that likely describe how paragraphs 10-12 contribute to the development of ideas in the passage are B and E.