Answer: i am 99% sure it is A
Explanation:
sedimentary rocks provide geologists with information necessary to study the history of earth.
Answer:
b or c i think. at least thats what i read
<span>Their progress and wealth is highly dependent on the harvests, and
the price of grain. They probably have to import some industrial
products and if they had a bad year (weather, other catastrophies, poor
technology) they can't get the necessary amount of industrial products
in exchange for their surplus e. g. in grain. </span>