A celestial body orbits the Sun. It consists of rock and ice. As it passes close to the Sun, the body forms a long tail of dust.

c.) polymerase chain reaction

- "unlike the original dna fingerprinting method, dna profiling does not use restriction enzymes to cut the dna. instead it uses the polymerase chain reaction (pcr)? to produce many copies of specific str sequences. pcr is an automated procedure that generates lots of copies of a specific sequence of dna."

a

explanation:

the answer would be knowledge about cars!

human-caused climate hope this