[解析]
(1)A.推理判断题。根据文章前两段得知加州大学的Harmer对向日葵做了一系列实验研究为什么向日葵会追随太阳的方向而变换方向。故选A.
(2)A.词义猜测题。根据文章第三段so that they could not move,它不能动和 sunflowers prevented from moving.阻止向日葵移动.得知划线词是"系紧"。A.Fastening系紧;B.Tracking跟踪;C.growing 成长;D.searching搜索。故选A.
(3)A.细节理解题。根据文章第三段"Harmer showed that he could destroy their ability to track the sun.He also noticed that sunflowers prevented from moving were not as tough and leafy as those that were free to move.哈默证明他可以摧毁他们追踪太阳的能力。他还注意到不能移动的向日葵并不像那些可以自由活动的向日葵那么坚韧和多叶。Harmer教授发现系紧向日葵后它们长得柔弱、叶子少。故选A.
(4)C.细节理解题。根据文章最后一段"The morning warmth changes the flowers in a way to make them more appealing to insects,perhaps causing them to release more attractive scents earlier in the day." 向日葵的向阳性使它变得温暖这样对昆虫很有吸引力。故选C.