Residents of three villages with three different sources of water supply were asked to participate in a survey to identify cholera carriers. becuase several cholera deaths had occurred lately, nearly everyone agreed to be examined. the proportion of residents in each village who were carriers was computed and compared. what kind of study was this? a. cross-sectional study
b. case-control study
c. prospective cohort study
d. retrospective cohort study
e. experimental study

a. Cross-sectional study

Explanation:

A cross-sectional analysis includes at one particular point in time looking at data from a population. Participants are chosen based on specific variables of interest in this type of study.

For developmental psychology, cross-sectional experiments are often used, but this approach is also used in many other fields, including social science and education.

enzyme active site and substrate specificity

enzymes bind with chemical reactants called substrates. there may be one or more substrates for each type of enzyme, depending on the particular chemical reaction. in some reactions, a single-reactant substrate is broken down into multiple products

the elements of art are the visual tools that the artist uses to create a composition. these are line, shape, color, value, form, texture, and space.

the principles of art and design are balance, contrast, emphasis, movement, pattern, rhythm, and unity/variety.