During the compression stroke of an internal combustion engine,

What even is this. where is the question

Answer(a)   the matererials that are in contact, the two materials and the nature of their surfaces/// (b)/// the force pushing the two surfaces together, pushing the surfaces together causes the more of the asperities to come together and increases the surface area in contact with each other

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

Lysosomes are considered  a digestive enzyme