NEED A BIO EXPERT TO HELP ME WITH HW!! Please answer if you have learned about this before, don't guess and explain your answer without plagiarizing from the web. I will pick brainiest - thanks

**THIS IS COLLEGE BIOLOGY - if you're in high school/middle school, don't even bother answering this

Aperson with age is more likely to catch diseases that healthy people usually don’t catch.what are these infections called?

The vaccine in a flu shot contains weakened flu viruses. how does a flu shot work with the immune system? a. it destroys lymphocytes. b. it destroys macrophages. c. it activates macrophages. d. it activates lymphocytes.

When does a spring tide occur? question 9 options: they occur when the sun, moon, and earth are aligned. in spite of their name, these tides occur twice a year in the spring and fall. they occur on the date of the vernal equinox each year, no matter what stage the moon is in. this is why they are called spring tides. they occur when the sun, moon, and earth are at 45-degree angles from each other. this happens once every spring. they occur when the sun, moon, and earth are aligned. in spite of their name, these tides occur all year long.