— I wonder what Mr. Wang asked you just now?
— He asked ________ .
A:whether I will take part in the singing competition
B:how long I have bought my new bike
C:what was wrong with my old bike
D:how much money did I spent on books
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 ( )