Which of the following was a social cost associated with the development of the internal combustion engine used in most cars? a. people were able to use their horses for new tasks. b. new jobs were created. c. blacksmiths needed to gain new skills to continue working. d. families were able to travel farther more easily.

~~16. while watching a special on animals, brianna discovers that hares tend to lose heat through their ears. based on this and what is known about surface-to-volume ratios, propose an explanation as to why hares that live in hot climates (such as the desert) have large, extended ears

Why do oceanic plates tend to subduction when colliding with a continental plate

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.