2. when any kind of wave bounces off a barrier, the bouncing back of the wave
is called?

giant impact theory - the moon was formed from the collision between earth and another mars-sized body.

colliding planetesimals hypothesis - the moon was formed from the same cloud of material as earth.

capture hypothesis - the moon was locked into orbit by earths gravity as it was passing by it.

accretion hypothesis - the moon was formed from collisions and combining of planetesimals.

i think this is right, if not and you know better let me know.

answer; the edward snowden leaks of nsa classified material;

answer; ///(3) three parts;