Are there regular languages between every two non-regular languages? I have a question regarding regular languages. Given that $L_1$ and $L_2$ are non-regular languages, can a regular language $L$ exist so it is a subset of $L_2$ and $L_1$ subset of $L$?

To be more specific:

$\qquad L_1 \subset L \subset L_2$

for $L_1, L_2$ non-regular Languages.
Hint. Given any sets $A, B, C$ we have $A \cap C \subset C \subset B \cup C$.