Which of the following is used as evidence that the universe began with the big bang?
a.
craters on the moon
b.
leftover energy in the universe from the event
c.
the force of gravity
d.
the existence of atoms

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.

15 points need quick 1. looking at your graph and the geologic time scale during what period did this rock form? what is the age span of the rock, in millions of years? 2. this rock sample is limestone and shale. with what you know about rock formation, what type of environment did these organisms live in? 3. if some of these fossil samples were found in a rock also containing leaf fossils, could you use radiocarbon dating to determine the age of this rock? explain.

What sequence of events connects the industrial revolution, industrial capitalism, communism, and the cold war?