Alli and her classmates want to know which species of oak produces the acorns that squirrels prefer. Which possible procedure is likely to produce the most reliable results? For one day, observe and record the number of squirrels that gather acorns from each species of oak. For three days, observe and record the number of squirrels that gather acorns from each species of oak. For five days, observe and record the number of squirrels that gather acorns from each species of oak. For seven days, observe and record the number of squirrels that gather acorns from each species of oak.

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.

Give an example of a situation in which an individual's pursuit of economic self-interest may not benefit but instead harm the rest of society

Name that largest artificial lake built in the 11th century