根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。 This short story about friendship is very inspiring and tells you about true friendship. 1 . Long time ago in ancient Greece,there was a respected philosopher named Socrates who was highly knowledgeable.He was visited by a man one day. 2 .Before he could even start talking about his friend,Socrates told him to take a test known as the Triple Filter Test (三重过滤考试) 3 .Socrates asked him if the information he w为探究食物相同的三种水生动物的种群增长规律及种间关系,某小组进行了下列3组实验(各组实验中,每种动物初始数量相等,饲养条件相同): 组1:甲种与乙种分别于两个容器中饲养,甲种数量变化如下图曲线A所示. 组2:甲种与乙种于同一容器中饲养.乙种数量变化如曲线F所示. 组3:乙种与丙种于同一容器中饲养,形成上、下层分离分布。一段时间后每种动物的数量均较组1少。 (1)组1中,甲种动物的种群数量主要由 和 决定;若容器内饲养液体体积为20mL,则第40天时乙种的种群密度为 . (2)在某些生态系统中,存在与本实验类似的种间关系. ①在同一段河流中食物相同的两种鱼,分别分布在河流中央底部和临近河岸底部,其种间关系与图中曲线 代表的类似,其分布体现生物群落的 结构. ②在玻璃温室中放养食物相同的两种传粉昆虫后,一种数量增加,另一种减少,其种间关系与图中曲线 代表类似.