Final answer:
Shield volcanoes have b. gentle slopes and are very large due to low-viscosity lava flows, while strato volcanoes are steep and moderately large with a layered structure caused by explosive eruptions.
Step-by-step explanation:
Shield volcanoes and composite (strato) volcanoes have distinct characteristics. The profile of a shield volcano can be described as having a b. gentle slope and they are typically very large in size. These volcanoes are formed by low-viscosity lava that can travel long distances before cooling and solidifying.
On the other hand, strato volcanoes are known for their steep slopes and are moderately large. These volcanoes are built up from layers of lava flows, volcanic ash, and other volcanic debris. Strato volcanoes usually have explosive eruptions due to the high viscosity of their magma, which traps gases and builds pressure.