It was my birthday yesterday. My friends bought some ____ for me.
已知数列an,那么“对任意的n∈N*,点Pnn,an都在直线y=2x+1上”是“an 为等差数列”的 ( )
100cm____2dm
9cm____9dm
被现代史学家郭沫若称赞为“政启开元,治宏贞观”的中国历史唯一的女皇帝是( )