According to source 1, which statement best explains the migration of early humans? Select one:
A. The rise of civilizations moved people to new places.
B. Natural disasters forced people to leave their native lands.
C. Religious conflict made people leave war-torn lands.
D. People searched for new sources of food.

50pts why can't scientists clone embryos for an unlimited supply of stem cells? culture of life: select the best answer from the choices provided. a. they do not yet have the technology to clone embryos. b. most scientists would never endeavor such a controversial task. c. there are already enough stem cell lines. d. cloning is prohibited by the human cloning prohibition act of 2003.

Endogamy is marriage within one’s own social category. select the best answer from the choices provided true or false

According to the federal regulations, which of the following studies meets the definition of research with human subjects? a study of twenty 4th grade classrooms in which researchers ask the schools to systematically vary the time of day reading is taught, and collect weekly assessments of reading comprehension for each child over a three-month period. the collection of data, by a playground designer hired by the superintendent of schools, about the physical dimensions of school playgrounds, presence of fencing, and the kinds of equipment currently provided. a feasibility study for implementing a year-round school program, focusing on economic issues such a facilities utilization and transportation costs. an analysis of aggregate data comparing statewide high school graduation rates provided by the state department of public instruction, using county tax information.