About 20 astronaut have faced fatalities during the space program.
Answer:
Spiral Galaxies, Elliptical Galaxies & Irregular Galaxies
Explanation:
How did galaxies originate? Astronomers believe that after the big bang, the explosion which began the universe 10 billion to 20 billion years ago, gravity began to compress masses of free-floating gas. Two main theories, bottom-up and top-down, explain what happened next. According to bottom-up theories, clusters began to form and assembled together into the larger units we know as galaxies. Top-down theories suggest that galaxies formed first, and the stars and other objects within them were subsequently produced. They categorized different galaxies to maintain their tests from the other galaxies.
Answer: A is for sure the answer
Explanation:
All of them are speciallized cell
#Muscle cells have evolved to carry out one highly specialized function — contraction. Muscle contractions must occur quickly and repetitively, and they must occur through long distances and with enough force to move large loads. ... A passenger car engine is only 1½ times more powerful than muscle.
#Reproductive cells include the sperm cell and egg cell. These cells have special features that allow them to come together and create a new organism that will grow and create specialized cells of its own!
#blood cells are highly specialized, well adapted for their primary function of transporting oxygen from the lungs to all of the body tissues. Red cells are approximately 7.8 μm (1 μm = 0.000039 inch) in diameter and have the form of biconcave disks, a shape that provides a large surface-to-volume ratio
#Most neurons have multiple dendrites, which extend out-ward from the cell body and are specialized to receive chemical signals from the axon termini of other neurons. Dendrites convert these signals into small electric impulses and transmit them inward, in the direction of the cell body.
SO ALL OF THEM ARE SPECIALIZED CELL BECAUSE OF THEIR SPECIFIC FUNCTIONS !