The first line of defense involves which structure(s)?

Chalk is an ionic compound. which is a property of all ionic compounds that makes chalkboard? particularly useful for writing on a a high melting point hardness and brittleness inability to dissolve in water a multicolored appearance

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

Dan made the table shown to describe two different relationships between animals. organism interactions relationship a relationship b one organism lives inside the organism it feeds off no organism is harmed which of the following statements is most likely correct?