When you drop a ball, it is dropped DOWNWARDS so the number is represented by a negative number. If you toss the ball up it will be a positive number.
To answer your question:
When an object is dropped downwards there will be a negative number since the object is falling downwards.
Answer:
solid layer of the mantle below the lithosphere
I’m not 100% sure what you are asking for but here is my explanation
The grouping of objects helps the shopkeeper because now the shopkeeper can find where everyone is faster. This will ultimately make taking inventory easier. As a result the efficiency of the shop and the shopkeeper will be faster. An efficient shop will result in better sales and overall will make the shop better.