选择题：“通奏低音”(Bassocontinu0或数字低音)是__________时期音乐的典型和声织体特征。

某陆地生态系统中，除分解者外，仅有甲、乙、丙、丁、戊5个种群。调查得知，该生态系统有4个营养级，营养级之间的能量传递效率为10％～20％，且每个种群只处于一个营养级。一年内输入各种群的能量数值如下表所

各抱地势，__________。(杜牧《阿房宫赋》)

Everyone becomes a little more forgetful as they get older, but men's minds decline more than women'

根据以下材料，回答Reading, like all work, has its rules. Aperfect knowledge of a few writers and a few subjec

大牧场放牧业的特点有 __________ 和__________。