21.   Prompted by rumors of cheating, professor Lou Bloomfield designed the computer program last month to catch students who had plagiarized term papers in his popular introductory physics class.

22.   Since this has not been conducted very much in physics classes, the outcome of physics classes in terms of thinking ability are meager improvements.

23.   When he entered high school, he insisted on taking an advanced physics class, over the objections of his teachers and counselors.