3. (3 points) label each example as either (pi) passive or (ai) active immunity:
a. bill had chicken pox when he was five. he doesn’t catch it again, even when his nephew gets sick with the virus
b. billy jr gets vaccinated with a live attenuated form of the chicken pox virus. he doesn’t get chicken pox after playing with his infected cousin.
c. bill’s 3 month old daughter is breast feeding. she does not get chicken pox after playing with her infected cousin.

1. loamy sand is about 80% sand with 10% clay and defined mostly by sand particles with some clay to provide structure and fertility. the sand particles are easily visible and the soil holds structure but breaks apart easily.

2. scott sand can improve his soil quality by incorporating more silt and organic matter into the soil. peat moss and organic matter can also be incorporated.

i think the answer would be d

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.