Which of the following processes begins when a star enters the main sequence? a

Nuclear fission
b

Nuclear fusion
c

Condensation of a nebula
d

Appearance of a supernova

3points hurry! what is the relationship between biotechnology, sharkskin, and disease resistance? bioengineers have developed an artificial sharkskin that does not allow resistant bacteria to grow on it. disease-causing microbes have been genetically modified to keep them from infecting the skins of sharks. scientists have created a device that can be attached to the skins of sharks that dramatically increases their abilities to resist disease. sharkskin produces many chemicals that can be collected and used to create antibiotics.

What is the average speed of a car that traveled 300.0 miles in 5.5 hours

Select the star life cycle that is accurate