若2x+3y﹣z=0且x﹣2y+z=0,则x:z=( )
A:1:3
B:﹣1:1
C:1:2
D:﹣1:7
— Why didn't you stay at __________ one?
“共争青岛归还,同看国贼罢黜;欢呼学生罢课,庆贺商店开门.”这首打油诗反映的重大历史事件是( )