1. eating healthy foods.
2. getting enough sleep.
3. getting enough exercise
4. managing stress
5. washing your hands consistently.
All of those things helps your immune system by strengthening it or by keeping germs away which intern helps prevent you from getting sick.
I hope this helps. Let know if anything is unclear.
it wont let me post it so i'll comment on the question box
Answer:
26= Relaxation Response/a
27= Priorities/e
28= Support Group/d
29= Re-channeling/c
30= Time Management Skills/b
I'm not for sure but it's what I think.
Hope I could help :D