A:-a-1
B:-a+1
C:-ab+1
D:-ab+b
已知a>0,x、y满足约束条件{x≥1x+y≤3y≥ax-3,若z=2x+y的最小值为32,则a= ( )
—No, but I like playing ________ chess.
某学生鉴定甲盐溶液的流程如图所示,下列说法正确的是( )