A:建设中国特色政党制度的需要
B:保持党的先进性的必然要求
C:提高党的科学执政的要求
D:提高党员的个人素养和水平的客观需要
已知两条直线ax-y-2=0和a+2x-y+1=0互相垂直,则a等于( )
—Would you mind taking the underground to the theatre tonight?
— .it will take less time than driving a car.