答案应该是A⊊C=B
由b/2-1/3=c/2+1/6 得b=c+1,
∴对任意c∈Z有b=c+1∈Z.
对任意b∈Z,有c=b-1∈Z,
∴B=C,又当c=2a时,有c/2+1/6=a+1/6 ,a∈Z.
∴A⊊C.
故答案为A⊊C=B.