Because the earth's climate is CONSTANTLY in flux and what today is a desert was once a tropical forest.
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Answer: b. Mao's political influence declined, as his policies had resulted in mass starvation" would be the best option from the list, but it should be noted that it took a while for Mao's influence to face, while the starvations happened immediately.
Explanation:
It would be battle of Leningrad where the soviets turned the Germans back and crushed them.
1 is running water and 2 is 3 and 4