A:树木
B:鲜花
C:珍珠
D:蘑菇
设直线l1,l2分别是函数f(x)= {−lnx,0<x<1lnx,x>1 图象上点P1,P2处的切线,l1与l2垂直相交于点P,且l1,l2分别与y轴相交于点A,B,则△PAB的面积的取值范围是( )
— How many ________ were on the bus when the accident happened?
— About forty. Seven of them were kids.
达尔文进化论使人们不再把动物和植物之间,动物和人类之间的区别看作是绝对的和神圣的,主要原因是进化论