In two or three sentences, explain why it can be difficult for people to practice delayed gratification

Spherocytosis is an inherited blood disease in which the erythrocytes (red blood cells) are spherical instead of biconcave. this condition is inherited in a dominant fashion, with sph- dominant to sph+. in people with spherocytosis, the spleen "reads" the spherical red blood cells as defective, and it removes them from the bloodstream, leading to anemia. the spleen in different people removes the spherical erythrocytes with different efficiencies. some people with spherical erythrocytes suffer severe anemia and some mild anemia, yet others have spleens that function so poorly there are no symptoms of anemia at all. when 2400 people with the genotype sph- sph+ were examined, it was found that 2250 had anemia of varying severity, but 150 had no symptoms. does this description of people with spherocytosis represent incomplete penetrance, variable expressivity, or both? explain your answer. (3 points)

Which step would a state health department most likely take to reduce lead exposure? promote health-planning operations to limit lead exposure at home.evaluate the number of countries affected by lead exposure.create general national guidelines for working with lead.carry out research on the worldwide effects of lead products.

Based on the chart, what are the three most effective methods to protect against pregnancy?