_________ is a disorder in which hard fibrous tissue replaces myelin, impeding neural transmission.
A) Autism
B) Multiple sclerosis
C) Down syndrome
D) Phenylketonuria
Question 2
According to the data accumulated by the National Center for Health Statistics in 2014, cancer and heart disease:
A) are the most common causes of death in young adults more than any other cause.
B) kill a smaller percentage of people aged 25 to 44 than aged 15 to 24.
C) take fourth and fifth place in the list of leading causes of death for teenagers and early adults.
D) are more frequently diagnosed in early adulthood than in middle adulthood.
