Searching for known subcircuits
We are not here to do your homework for you.  If you really knew these sub-circuits, they would jump out at you.

However, look up things called differential pair, darlington, and cascode.  You should not only just try to identify them, but study them to understand how they work in their own right.  These can be useful building blocks when designing circuits, but more importantly, the concepts behind them are essential for designing a wide variety of circuits.

This is a worthwhile assignment, even if it appears to be just about silly naming conventions at first glance.