亚洲是____ 人种的故乡,撒哈拉以南的非洲是____ 人种的故乡.
已知过原点O的直线与函数y=log9x的图象交于A,B两点,分别过A,B作y轴的平行线与函数y=log3x的图象 交于C,D两点,当BC∥x轴时,A点的横坐标是( )
﹣0.78,5,+ 14 ,8.47,﹣10,﹣ 227 ,0, 13 , π3 , 0.3·1· ,﹣2.121121112…
整数集合:{____…}
分数集合:{____…}
有理数集合:{____…}
无理数集合:{____…}.
I don't really r like the write, I have to say his books are very exciting.