Answer:
At different times
Explanation:
The echo returns at different times, but faster in water. This is because water particles are bound closer and this makes them transmit vibration energy from one particle to the next quickly. An echo is a sound wave and sound waves are longitudinal waves that occur by the collision of particles to move the vibrations along, and this is why they move slower in air.
Answer:
Concrete operational thinker.
Explanation:
Dee has now become a concrete operational thinker because she has now grown to think more rationally.
This stage by Piaget is the 3rd in his theory of cognitive development. Dee is now mature enough to use logical reasoning. From what we can see, her thinking is now more concrete and sophisticated. But she can only apply this logic to physical objects.
Not 100% sure to be honest.. i’m sorry :( i wish i could help.
Its mostly a stylistic choice although at one points it was mostly a heat related idea. Hot air rises so having a steep roof allowed for the accumulation of hot air. It was also a good windbreaker so a collection of houses were able to stop a lot of the harsh wind from damaging things.
