When mechanical energy is transformed, A.
potential energy remains unchanged.
B.
heat is given off.
C.
kinetic energy remains unchanged.
D.
friction is encountered.

space exploration has led to the development and technological improvement of many everyday items. (if this answer is wrong i will find the right answer) : )

the cold front replaces the warmer air at the ground level changing the wind to be breezy and denser.there is also an immediate drop in the temperature.

colorless gas, exhibiting a blue glow when placed in an electric field

b) solid

its a type of rock