森林里,松鼠、猫头鹰等多在上层活动,大山雀、柳莺等在灌木丛活动,而獐、野猪则在地面活动,这种现象反映了:( ) A.种群密度 B.种群增长率 C.群落的垂直结构 D.群落的水平结构 答案:C
问答配对。
( )1.Thank you very much.
( )2.May I speak to Mr Smith, please?
( )3.How's the family?
( )4.I'm sorry to give you so much trouble.
( )5.I haven't passed the exam.