What do the orange and yellow spheres represent in this model of an atomic nucleus?[Atomic nucleus] A Gluons and leptons
B Protons and neutrons
C Positrons and electrons
D Atoms and molecules

Describe the primary and secondary immune response in terms of speed and number of antibodies produced?

The hypothesis of continental drift states that earth's continents, which are located on tectonic plates, move relative to each other. which of the following is true of the movement of the tectonic plates? a. tectonic plates only move once every million years. b. they move at a rate of approximately 5 centimeters per year. c. tectonic plates never move, only the continents located on them do. d. their movements are very rapid and occur at random times.

Where do the respiratory and circulatory systems meet? a. in the heart b. in the muscles c. in the lungs d. in the brain