Julia's father, Mr Green is 40 years old. He has two brothers and three sisters. Julia's mother, Mrs. Green is a farmer. She has two brothers and two sisters. Julia has a brother, his name's Ben. Look! Ben is on the sofa. Julia is on the chair. Ben likes sports.He has basketballs and footballs.Julia doesn't like sports, she likes reading books.

在探究“根的什么部位生长最快”的实验中，各组同学获得的数据不同，为了得到接近反映真实情况的数据，应该（　　）

在弹簧测力计悬挂一圆柱体，从盛水的烧杯上方某一高度缓慢下降，圆柱体浸没后继续下降，直到圆柱体底面与烧杯底部将要接触为止（水未溢出），如图所示是圆柱体下降过程中弹簧测力计读数F随圆柱体下降高度h变化的图象。求：