1.which is the best unit to use when measuring the length of a car: a meter or kilometer?

Need now! 45 points laboratory: weather map interpretation i need someone to answer the other two questions. i will give to the best answer!

Which of the following can scientists estimate geologic time? a.observing rock sequences b.radiometric dating c.comparing fossils d.all of these

Which revelation resulted from the observation of the spectrum of different galaxies? a. there were more galaxies whose spectrum was blueshifted b. there were no galaxies whose spectrum was redshifted c. there were more galaxies whose spectrum was redshifted d. there were no galaxies whose spectrum was blueshifted