1) Which object will most likely be repelled by the metal sphere?

A) a magnet with its South Pole facing the sphere

B) a glass with a positive charge

C) a magnet with its North Pole facing the sphere

D) a paper with a negative charge

What even is this. where is the question

If there was no gravity then their would be no downword force on the football to have it return the the grownd, and if there was no friction (mainly air friction) then there would be no opposing force the stop the ball from moving through the air allowing the ball to travle ∞.

The fertilized egg  begins to develop into a hollow ball of cells called the blastocyst. 

Sounds propagates through some kind of medium. usually it's air, but it goes just as well through solid objects like walls, windows etc. a soundwave will compress the (air)molecules in front of it, and if this increased density wave hits your ears, you register it as sound. solid objects like walls are a lot denser than air, this means that they will damp a wave, but also carry it easier.