——Do you know ____ boy who can play ______ violin? ——Yeah! He is ___ artist. He also plays ___ football very well.
A:a; a; the; /
B:The; a; a; the
C:the; the; an; /
D:The; an; a; /
近年来,许多地方政府“晒”出了权力运行流程图,明确规定行使权力的条件、承办岗位、办理时限、监督制约环节以及廉政风险防控等,方便群众“按图索骥”给予监督。这一做法的积极影响是( )
设变量x,y满足约束条件y≥0x-y+1≥0x+y-3≤0,则z=2x+y的最大值为 ( )