In the ancient world, why did civilizations flourish around great river valleys? River valleys protected citizens from natural disasters,
O River valleys provided an ideal environment for agriculture,
e River valleys sheltered citizens from harsh weather,
O River valleys contained vast mineral resources,

Excerpt from w. e. b. du bois jon reese 4 du bois was one of the first male civil rights leaders to recognize the problems of gender discrimination. he was among the first men to understand the unique problems of black women, and to value their contributions. he supported the women's suffrage movement and strove to integrate this mostly white struggle. he encouraged many black female writers, artists, poets, and novelists, featuring their works in his crisis magazine and sometimes providing personal financial assistance to them. the cause was that w. e.b. du bois encouraged many black female writers, artists, poets, and novelists. what was the result? think about cause-and-effect relationships.

Lincoln fought to prevent secession from the united states of america. true or false?

Some organisms have a large geographic range. for example, the norway rat lives on every continent except antarctica. a population of norway rats is the number of rats in one particular area. do you think it’s scientifically possible for a population of norway rats in north america to carry different genetic mutations than a population of norway rats in africa? do you think it’s possible that they carry some of the same mutations? what types of information can scientists learn by studying the genomes of these two populations of rats?