Good morning!! can someone help?!:)

An energy drink company claims that its product increases students' memory levels. to support its claims, the company issues advertisements claiming that 8 out of 10 people (chosen randomly from across the country) who tried their product reported improved memory. the missing component in this study is a .

Ade and abc are similar. which best explains why the slope of the line between points a and d is the same as the slope between points a and b?

Which diagram shows lines that must be parallel lines cut by transversal?