21.   As theories of cognitive dissonance suggest, people can change their ideas and beliefs relatively quickly and easily in response to a changed external environment.

22.   At that moment, people change the design of their Web site.

23.   Because of stiff competition among carriers, many people change carriers and get new phones.

24.   Because people change e-mail addresses often, bulk e-mail lists have a high percentage of invalid addresses.

25.   A native of Taiwan who left the island because, he said, it was too chaotic, Lau said people have changed the way they ask questions.

26.   A few years ago, the SAT people changed the scoring on its exam.

27.   A study released Monday by the Pew Internet and American Life Project found that people changed their activities both on and off the computer when they acquired broadband service.

28.   But he said the cost of driving still had not reached high enough levels to cause people to change their driving practices.

29.   But is even that much benefit enough to get people to change entrenched eating habits?

30.   But people change.