Answer:
He wanted to sail to East Asia. He wanted to sail to India, China, Japan and the Spice Islands so he could get valuable silks and spices. Columbus knew the world was round.
Answer:
A black hole is a region of spacetime exhibiting gravitational acceleration so strong that nothing. No particles or even electromagnetic radiation such as light, can escape from it.
Shale/Coal/Oil are the most important mineral resources in Appalachia and are used as a source of energy by many in the world.
Answer:
This is an example of habituation.
Explanation:
Habituation refers to the decrease in the response to a stimulus after a prolonged exposition to that stimulus. In the situation we are analyzing here, you are experiencing habituation. The stimulus - the sound of the tornado siren - no longer provokes a response from you. When it was a novelty, something you hadn't gotten used to yet, you would be startled. However, after hearing it over and over again, you no longer jump at its sound. You are now habituated to it.
That is very true heat for the crops