An instructor hypothesizes that doing jumping jacks will improve his students' quiz performance. On Monday, he has his class sit in their chairs for 5 minutes before completing a multiple-choice quiz on their reading assignment. On Wednesday, he has his class do 2 minutes of jumping jacks before completing the same quiz that they took on Monday. The students performed better on the quiz on Wednesday. Which is a possible threat to internal validity in this study?

the correct answer is the following is a list of inventions made in the medieval islamic world, especially during the "islamic golden age" (8th to 13th centuries),[1][2] as well as the late medieval period, especially in the emirate of granada and the ottoman empire.

science and technology in the islamic world adopted and preserved knowledge and technologies from contemporary and earlier civilizations, including persia, india, china, and greece-roman antiquity, while making a number of improvements and innovations.

answer; having the power of reprieve means being able to release people from punishment;