Question 22 is based on the passage you have just heard.

Passage Three

听力原文

    Watching more than 3 hours of television a day doubles memory loss in older people, a new study of more than 3,000 adults suggests. (22) [Scientists at University College London used memory and fluency tests on the same group of people 6 years apart.] They found that those who watched on average less than 3 hours’ television a day showed a decline of around 4 to 5 percent, while those who tended to watch more than 3 hours a day declined by an average of 8 to 10 percent. (23) [The research team say they believe the “alert-but-passive” nature of television watching may be creating stress on the mind, which contributes to memory decline.]

    Older people who watch more television are also less likely to undertake activities known to preserve mental functioning, such as reading, or interactive screen-based pursuits such as using the Internet or playing video games. (24) [The researchers say that television viewing may be a risk factor for Alzheimer’s disease, but more research is needed to establish a link.]

    While watching television may have educational benefits and relaxation benefits, (25) [the researchers advise that adults over the age of 50 should try and ensure that television viewing is balanced with other contrasting activities.] If you’re concerned that the amount of television you’re watching could have a negative impact on your health, you should limit the amount of TV you watch each day and undertake some healthy hobbies.

22. By what means does scientists at University College London measure memory loss?

解析：C。根据选项中反复出现的By以及选项内容推测本题考查做某事的方式方法。录音中表示，伦敦大学学院的科学家对同一批人进行了两次记忆力和流利度测试来测量记忆力减退的程度，因此C选项符合题意，memory and fluency tests为原词复现。

错项排除：录音中虽然多次提到人们看电视的时间，但它并不是衡量记忆力减退程度的方法，故排除A项。B和D两项在录音中均未提及，故排除。