A:twice as many
B:twice as much
C:as twice as many
D:as twice much
党中央首次阐明社会主义初级阶段理论,作出社会主义初级阶段经济发展分三步走的战略部署是在( )
运行如图的程序框图,若输出的y随着输入的x的增大而减小,则a的取值范围是____