Researchers study identical twins to examine how personality. heredity culture family environment

The answer is the fourth option "environment." Since how identical twins both develop their own genome researchers want to study their differences that were caused by the environment.

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explanation:

eventually, the disease can cause permanent damage or deterioration of the nerves. some people with ms experience a gradual onset and steady risk factors.

1 true

2 true

and 3 true im assuming these are true or false. hope this