Which part of the atmosphere is the highest layer in which planes can fly?

a. stratosphere
b. troposphere
c. mesosphere
d. thermosphere

If a particular resource is not useful or needed then the price would be considerably low. once that resource is needed the price or value will raise depending on how useful or needed it is especially if the resource is low in quantity, the consumers would pay whatever they have to, to get that material.

The fact that the earth goes through natural cycles for example the ice age some scientists belive that it is just another cycle

Think it's d