23. "How do seed-eating animals affect the distribution and abundance of the trees?" This question
(A) would require an elaborate experimental design to answer.
(B) would be difficult to answer because a large experimental area would be required.
(C) would be difficult to answer because a long-term experiment would be required.
(D) All options are correct.

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統計： A(10), B(9), C(23), D(78), E(0) #781188