①Excel ②FrontPage ③Access ④PowerPoint( )
A:②③④
B:①②③
C:①③④
D:①②③④
I really don't know the answer. I'm just guessing.
(1)用辗转相除法求840与1764的最大公约数.
(2)用更相减损术求561与255的最大公约数.