题目

某实验小组对某地处于不同放牧强度下伊犁绢蒿种群特征及其群落多样性进行了研究，结果如下图所示，下列叙述错误的是（ ）注：LG:轻度放牧，MG:中度放牧，HG:重度放牧，CK:对照区A.各年份伊犁绢蒿种群密度均在轻度放牧情况下达到最大，重度放牧下达到最小B.各年份随放牧强度增加，丰富度指数都呈现增加趋势，且重度放牧高于对照C.调查表明适度放牧利于增加该地群落的丰富度，以此维持草地群落的稳定性D.2013年物种丰富度高但种群密度却低可根据文章意思，填出文中所缺单词。 Dear Mother, 　　I am in Beijing now. I ________ at No.4 Middle School. The ________ is very big and beautiful. There are many teachers and students in the school. The ________ love the students very much. The ________ love the teachers, too. My favourite subject is ________. I like playing computer. I want to be a computer teacher. I am very happy here. 　　See you soon. Love, Wang Ping