选择题：Psychological research has focused on a number of

Psychological research has focused on a number of basic principles that help memory: meaningfulness, organization, association, and visualization. It is useful to know how there principles work. Meaningfulness affects memory at all levels. Information that does not make any sense to you is difficult to remember. There are several ways in which we can make material more meaningful. Many people, for instance, learn a rhyme to help them remember. Do you know the rhyme "Thirty days has September, April, June, and November..."? It helps many people remember which months of the year have 30 days. Organization also makes a difference in our ability to remember. How useful would a library be if the books were kept in random order? Material that is organized is better remembered than jumbled information. One example of organization is chunking. Chunking consists of grouping separate bits of information. For example, the number 4671363 is more easily remembered if it is chunked as 467, 13, 63. Categorizing is another means of organization. Suppose you are asked to remember the following list of words: man, bench, dog, desk, woman, horse, child, cat, chair. Many people will group the words into similar categories and remember them as follows: man, woman, child; cat, dog, horse; bench, chair, desk. Needless to say, the second list can be remembered more easily than the first one. Associati