Answer:
cali is dry outside of the mountains
GAO report said hundreds of planes flying commercially today could be vulnerable to having their on board computers hacked.
The correct answer is - currency.
The objects or group of objects that have been widely agreed upon to be used a s form of exchange is called currency. The currency is a very useful method for exchanging things, and it has been widely accepted around the world, with some currencies being globally accepted, while some only regionally, or locally.
The reason why the currencies have been introduced is so that the two or more sides in the process of exchange have the same means and valuations, thus making the exchange very easy. Some of the strongest currencies in the world are the American Dollar, Euro, British Pound, Swiss Frank...
D. urbanization is always good for the environment
The correct answer is - B. convection currents in Earth's mantle.
The movement of the Earth's tectonic plates is driven by the convection currents. The convection currents appear in the mantle layer, and they are currents made out of molten metals with high temperature and very high pressures.
Those high temperatures and pressures have resulted in cracking the crust on the surface of the Earth, thus creating multiple tectonic plates, some very large, some very small.
The pressure from the convection currents is so high that it actually manages to move the plates in certain direction, making them collide/subduct, slide past one another, or move away from one another, shaping up the physical geography of our planet.