As people age, the immune system produces fewer _________ and the disease-fighting ability of those that remain declines.
A) ova
B) red blood cells
C) platelets
D) white blood cells
Question 2
According to Jeffrey Arnett, _________ is a feature that distinguishes the stage of emerging adulthood.
A) stability
B) self-focus
C) lack of possibilities
D) resolution of the problems associated with a revolving door existence