Which statement is correct about Newton's law of universal gravitation?
1. It is a rule that changes at regular intervals.
2. It is a societal law because it is sometimes true.
3. It is a scientific law because it is always true under the same conditions.
4. It is made by a government.

It is a rule that changes at regular intervals.

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."

your body is trying to warm itself up. or more precisely, sensors in your skin send messages to your brain to generate heat to your body.