Answer:
1 = A
2 = B
3 = B
Explanation:
1) Black holes occur when really big stars collapse on themselves. And, in order to get big, the star has to be an old one.
2) A black hole is something huge that swallows up everything, while a protostar is just the very beginning of a star.
3) Scientist can't truly know for sure, but they can infer about them due to the effects of the surrounding areas.
Osmosis is basically the spread of water across a particular absorbent membrane.
<span>The organic chemicals that help
cell membranes to conserve internal fluids are the phospholipids. They are
composed of fatty acid, glycerol, phosphate group and a polar molecule. The phosphate
group and polar head region of the phospholipids is attracted to water while
the fatty acid is repelled by water. They are a major component of the cell
membrane in which it encloses the organelles of the cell. It also limits what
enters and exits the cell because of its two heads.</span>
