Achild who can understand adding and subtracting by using blocks, but cannot think logically about these abstract concepts when done woth numbers on paper, is probably in the_stage

Preoperational is the answer

changes in factors like average income and preferences can cause an entire demand curve to shift right or left. this causes a higher or lower quantity to be demanded at a given price. demand curves relate the prices and quantities demanded assuming no other factors change. it is important for consumers to know this information, because it is crucial for them to know what they can afford and can't afford. i hope this .

the vibration from the sound waves messed with the glass and it shattered.

hope this .