Does the language $\{(1^n2^n)^t \mid t,n\ge0\}$ contain the string $121122$?
$t$ and $n$ are independent numbers. Any string in the language consists of $t$ units, where each unit consists of $n$ $1$s followed by $n$ $2$s.  In particular, then, the string generated by any choice of $t$ and&nbsp;$n$ contains $tn$ $1$s and $tn$ $0$s.