Which organ system includes the esophagus, pancreas, and large intestine?
a) digestive
b) excretory
c) integumentary
d) lymphatic

In a stagnant pool of water, a crayfish may spend much of its time lying with one side of its carapace near the surface of the water. in this position, it will move the walking legs on that side in a rhythmic back-and-forth motion. explain the likely function of this behavior.

What are similarities and differences of reflection, refraction, diffraction and absorption?

What is a carrier wave and how does it affect what you hear on the radio