方程（x-1）（x-2）=0的两根为x1，x2，且x1>x2，则x1-2x2=（ ）。
0
- Are they soccer with the school team on Wednesday?
- No, they have to go to a party.
A．played
B．playing
C．play
D．to play
“单单一致”的纵审时，以( )为中心。
A．保险单 B．商业发票 C．海运提单 D．装箱单
