D. They worked as agriculture laborers.
<span>First a science fair requires projects. They should be a diverse group of experiments and demonstrations. Second, the students should be present and close by their project so they can explain their work. The third important component of a successful Science Fair is community mentors to act as judges. The judges should interact with the students, make fair decisions, and spark interest in science.</span>
<span> this method, which can use over 100 questions, gathers : biodata
Biodata is a set of file that consist of factual information about an individual, including facts such as name, age, gender, hobby, height, marital status, favorite song, etc.Researcher often use biodata to screened out the potential subject for their research</span>
