How do Earth's crust and mantle differ? A. The crust is thinner and less dense
B. The crust is thinner and denser
C. The mantle is thicker and less dense
D. The mantle is thinner and denser
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Mention true or false : a) cholera is marked by acute diarrhea and no urination. b)mosquitoes are the source of dysentery germs.

Even though the ostrich is a flightless bird, ostriches still possess wings that stretch approximately two meters across when fully extended. scientists speculate that when dinosaurs became extinct, some of the birds that lived during that time became land dwellers since they were able to consume the food that the dinosaurs once ate. over time, these species grew larger and heavier. eventually, the ostrich species became too big to fly. the wings found on ostriches are known as a. analogous structures. b. homologous structures. c. vestigial structures. d. symmetrical structures.

Which of the following statements is true regarding a basic amino acid? a.) the hydrophilic r group of a basic amino acid will be located on the interior of a protein b.) the positively charged r group of a basic amino acid could bind dna c.) the r group of a basic amino acid would only be able to form covalent bonds with other molecules d.) a basic amino acid would be considered both polar and hydrophobic e.) all of the above