select the correct answer.

what is the purpose of this excerpt from the article "what is gis? "?

gis also can be used for complex modeling to answer a wide range of "what if" and ecosystem simulation questions. these may be cartographic models designed to document the co-occurrence or interrelationship of multiple data layers or they may be hypothetical research models designed to mimic natural ecological systems. similarly, modeling with gis can be used to predict the impacts that one set of parameters will have on another. for example, wetlands, soils, hydrography, climatology and elevation data can be combined to model flooding within a river system. upstream changes in land use within the same system can be modeled to determine the potential impact of conversion of a forested floodplain to residential development or to agriculture. as a result, both natural system responses to storm events and the impact of human land use decisions can be assessed prior to the proposed action.

Read sentence 13 from the draft. some plants retain a great deal of their foliage through much of the spring and summer, but the leaves do not retain their green color for long. which detail would be best to add after sentence 13 to develop the topic? a. since the green color of the leaves that are bright and abundant during the warmer months will disappear by the time it is fall, it is important that the leaves are trimmed and kept freshly cut so that they will last for as long as possible. b. while the temperature outside may dictate when the fall colors of leaves appear, it is only one of many environmental factors that play a part in the changing of colors from green leaves to fall-colored leaves during the cooler months. c. if people want to enjoy the green color of leaves longer, trees should be planted where the environment is warmer and the days longer because chlorophyll in the leaves can only be manufactured and replaced with sunlight and warmth. d. the green chlorophyll normally masks the fall-colored pigments during the warmer months, but as sunlight becomes less abundant and trees become frozen, the fall colors of leaves become more visible as chlorophyll disappears.

Read the sentence. thomas jefferson himself worked on a draft of the document. what kind of pronoun is himself?

In  the earth is precious, chief seattle says that man did not “weave the web of life, he is merely a strand in it.” what attitude is he implicitly criticizing by saying this?