How do index fossils scientists? a .they aid in the study of ranges of different organisms. b. they advance understanding of the origin of life on earth. c. they aid in comparison of rock layers at distant locations. d. they advance understanding of rock type at the time the organism lived.

In the late 1990s, brazil’s poor people protested about crowded cities land distribution mining permits industrial pollution

Concealer circle oh in which arc xy measures 16 pi centimeters the length of the radius of the circle is 32 cm what is the circumference of the circle

Scientist: cross-sections of stalactites—calcite formations deposited on cave ceilings by seeping water—can reveal annual variations in rainfall in particular areas over hundreds and thousands of years. we often found that when—according to these cross-sections—drought occurred in a particular area, it coincided with the collapse of an ancient society in that area. i hypothesize that drought reduced agricultural productivity in these areas, thereby leaving these societies without the resources needed to handle internal stresses and external threats. which of the following, if true, would most weaken the support for the scientist's hypothesis? a. many droughts indicated in the cross-sections of stalactites do not correspond with the collapse of a society in that area. b. information from the cross-sections of stalactites alone cannot reveal the level of agricultural output in an area at a particular time. c. most of the societies that collapsed during droughts did so when internal power struggles coincided with military raids from neighboring societies. d. most of the societies that collapsed during droughts maintained large stockpiles of food and water at the time of their collapse. e. information from stalactites also suggests that the collapse of some societies coincided with periods of abnormally high rainfall.