TOEFL Reading: ETS-TOEFL阅读机经 - 33V4RF0MW6772475L$

According to paragraph 4, which of the following is NOT an adaptation that helps ensure that pollen travels as far as possible? A. Pollen-producing flowers and catkins are located at or near the top of the tree. B. Trees grow at least 100 meters away from each other. C. Dangling catkins release pollen only when the wind is blowing hard. D. Pollen is not released during rain storms or when the air is damp.