Which geographic features have acted as barriers that divided Central Asian peoples for much of their history?
A. Fertile plains
B. Mountain ranges
C. Rivers and seas
D. Arid deserts
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What process allows for the development of haploid sex cells? mitosis meiosis fertilization pollination

Which of these resources is used worldwide to make construction products, pottery, and porcelain

Researchers randomly divide participants into groups. each group takes a different amount of omega-3 fatty acid supplements daily for a month. one group receives a placebo. the researchers measure the impact on cholesterol levels in the blood. what is the purpose of random assignment in this experiment? a, to produce treatment groups with similar characteristics b, to ensure that all people with high cholesterol have an equal chance of being selected for the study c, to increase the accuracy of the research results and prevent skewness in the data