Why is classifying organisms important, whether it's at a zoo or studying many organisms found in nature

Using complete sentences, describe the central economic problem facing all humans. why does this require people to make choices? how can this result in opportunity costs?

Rectangle qrst is shown. angle qrt is congruent to angle str, and angle str is complementary to angle qtr. which statement is true about angles qrt and qtr? they are congruent. they are complementary. they are supplementary. they are right angle

Where does the availability of water pose the greatest problem