Everybody except Mike and Linda there when the meeting began.
A:is
B:are
C:was
D:were
①若|z1﹣z2|=0,则 z1¯ = z2¯ ②若z1= z2¯ ,则 z1¯ =z2
③若|z1|=|z2|,则z1• z1¯ =z2• z2¯ ④若|z1|=|z2|,则z12=z22
其中真命题的序号是____.