①以人为本 ②全面发展 ③协调发展 ④可持续发展
A:①②③
B:①②④
C:①③④
D:②③④
函数y=log22x-1的定义域是( )
—People now can know what is happening in the world quickly. —You're right.With the help of computers,news can ___every corner of the world.