The nsa could be hiding small snooping programs in, let's just say, a picture of a cute kitten or a fun android game." so how can the average joe ever know that what they download is the real picture or app with no hidden malware in it?

One way could be to check the code of the program.
But of course this might not be possible... Not everyone knows a programming language. And even if you did, you might not know the programming language they used.

Another way is to download a program that monitors your incoming connections and outgoing connections from your computer/android/iphone.

When someone or something connects to your device, the program should alert you. Or when the computer makes a connection to a website/device.

Through the process of sedimentation,sediment is turned back to rock to form sedimentation.the process of sedimentation is: > deposition-where fragments were deposited into the river or sea under gravity or travelling agent such as wind or water. > sedimentation-the fragments deposited in the river sedimented and accumulate> compaction-the layers of fragments deposited undergoes compaction due to the weight if the upper layers> cementation-chemical substance of the fragments such as cement dissolved into the water and cement the other fragments together to form sedimentary rock.thus,cementation and compaction are the process.on the other hand, transformation only occur when a rock under goes metamorphism(compaction or extreme heat).while recrystillization occurs when a rock is melted and cooled down,which also requires metamorphism to take place.hope it !