Which of these is a way the immune system works with other body systems? A. Lymph nodes are the site of red blood cell production. B. Enzymes in the digestive system kill pathogens.
C. Lymph is filtered through parts of the skeletal system.
D. White blood cells produce mucus in the nose.​

answer: oof wait

explanation:

if the type of the food available changes, then the frequency of beak types will change, because birds with beaks more suited to the available food will be more successful over time.

sex cells are usually half's then they find another half and make a fertilize egg