Which of the following statements is the best explanation for why the embryos look so similar, considering how different an adult fish and pig are? Fish and pigs both need gills. Fish and pigs are both mammals. Fish and pigs share a common ancestor.

What is the typical rotational frequency frot for a molecule like n2 at room temperature (25∘c)? assume that d for this molecule is 1å=10−10m. take the total mass of an n2 molecule to be mn2=4.65×10−26kg. you will need to account for rotations around two axes (not just one) to find the correct frequency. express frot numerically in hertz, to three significant figures.