应该用aren't they的.
陈述部分的主语是everybody,somebody,anybody,nobody,everyone,no one,none,either,some one时,其后的反意疑问句用主语they以兼顾所指代的男、女两性.有时也用单数he.
eg.Everyone knows the answer,don't they?(does he?)
① Everybody has got the new books,haven’t they?
所以这里是不能用it的.
但是如果陈述句部分主语是everything,something,anything,nothing时,其后的反意疑问句主语用it.
eg.① Everything seems all right,doesn’t it?
②Nothing is in the box,is it.