Here's why:
* Explosive eruptions produce layers of ash and pyroclastic debris.
* Non-explosive eruptions produce layers of lava flows.
These alternating layers build up over time, creating a tall, conical volcano with steep slopes. This is the defining characteristic of a stratovolcano.
Examples of stratovolcanoes:
* Mount Fuji (Japan)
* Mount Vesuvius (Italy)
* Mount St. Helens (USA)
* Mount Rainier (USA)