The diagram shows structures that form the surface of the trachea. Which level of organisation is the structure labelled S?
A. Cell
B. Organ C. Organ system
D. Tissue

7th grade question (easy) look at the diagram of the food web. the arrows mean eaten by. what would happen if the number of snakes went down? answer choices are in the image.

Restless tectonic plates move (shift) between one and fifteen centimeters per year month day minute

What substance is the most acidic. lemon juice. tomato juice. sodium hydroxide. water