A:Instead of
B:Other tha
C:Except for
D:Apart from
下列实验室制取CO2的方法不合理的是( )
解方程组:
(1){2x+3y-z=32x+6y+z=-22x-3y+z=-5
(2){x+y-2z=-22x+6y+z=2x+y+z=0
(3){9x+5y+z=-69x+y+4z=3-9x+3y-5z=0.