Nylon fiber is classified under which one of these headings?
a. protein
b. polyurethane
c. polyester
d. polyamide

How are fossils most commonly formed

Ascientist is designing an investigation to study the impact of invasive bird populations on local, native bird populations at backyard bird feeders. what population is most likely to be a control group for the investigation? amount of food number of bird feeders invasive bird populations local backyard birdfeeders without food

Kate is studying the transformation from unicellular to multicellular organisms. which metaphor is the most appropriate to apply to the map of the timeline.