题目

放牧生态系统是由食草动物、草地植物、微生物等及共所在地的非生物环境组成的某植物种群密度与出生率、死亡率的关系如图所示。下列相关叙述不正确的是（ ）A.据图可知，随着该植物种群密度的增加，出生率降低，死亡率升高B.在生态系统中，所有种群和生物群落内部都普遍存在负反馈调节机制C.若该植物种群密度长期维持在K值，则该生物群落没有发生群落演替D.每种牧草的种群密度变化均受自身生长速率和食草动物采食速率影响 仿照从课本上摘抄的例句，将所提供的零乱的单词组成完整的句子。 Work and study today are very different from what they were like 20 years ago． 1．you Can what like 2008 imagine Olympics will the be? _________________ 2．looks The dish from cooked what like differently it was you it last． _________________ 3．used has A hotel built what been to be at a wasteland． _________________