Classify the following as either a specific or a nonspecific defense of the body's immune system.

- skin
- macrophages
- bacteria
- mucous
- fever
- b cells
- t cells
- antibodies

An object moves from position +34m to the position -15m in 15 seconds. what is the total displacement? what is the total velocity?

Which lists the pairs of plates in order from least to greatest in terms of the work done to move the electron?

Which of the following correctly describes what happens when an atomic bomb explodes? small pieces of fissionable material are joined and form a body with a mass greater than the critical mass, the relative number of neutrons escaping decreases, and a chain reaction and explosion result. large pieces of fissionable matter are brought together quickly and form a body with a mass smaller than the critical mass, the relative number of escaping neutrons increases, and a chain reaction and explosion result.