Which of the following is a part of a rock formation that consists more or less of the same type of rock minerala. bedb. fossilc. eventd. stratum

In 1933 the 21st amendment was added to the u.s. constitution, allowing for the manfacture, transportation, and sale of alacoholic beverages in the united states. why was this amendment needed?

Witch one is it soo it the the question b.a,b,c,d

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.