What physical feature once served as a natural boundary to western expansion? Group of answer choices

the Mississippi River

the Great Plains

the Great Lakes

the Appalachian Mountains

Which of the following countries has declared itself nuclear free

Danielle has blonde hair. her mother has blonde hair and her father has brown hair. which explains how danielle inherited her hair color? she inherited a chromosome that carry alleles for hair color from someone other than her mother and father. she inherited a chromosome that carries an allele for hair color from only her father. she inherited a chromosome that carries an allele for hair color from only her mother. she inherited a chromosome that carries an allele for hair color from each parent.

Impressions of tropical swamp plants were observed on rocks in polar regions. the impressions were dark black imprints, which means the fossils are examples of ( 1 ) the fossils tell us that polar regions ( 2 ) ( 1 ) a. carbonization b. mineralization c. trace fossils ( 2 ) a. had tropical plants that can grow in ice b. might have had a diffierent climate in the past c. will have abundent vegitation