阅读下面这篇短文，短文后有2项测试任务：(1)第23～26题要求从所给的6个选项中为第3～6段每段选择1个正确的小标题；(2)第27～30题要求从所给的6个选项中选择4个正确选项，分别完成每个句子。 Exercising Your Memory 1
Aging does not mean a dramatic decline in memory power, unless you help it
happen by letting your mind go. 2 That’s not to say that memory doesn’t
change throughout life. Researchers divide memory into categories based on the
length of time when memories are stored. One system divides it up as short-term
(less than one minute; remembering a telephone number while you dial, for
instance), long-term (over a period of years) and very long-term memory (over a
lifetime). 3 Short-term memory isn’t mastered until about age 7, but
after that you never lose it. Long-term memory, however, involves more effort
and skill and changes more through life. It’s not until the early teens (十几岁)
that most people develop a mature long-term memory. 4 First, we must
get information into our heads through learning. Learning strategies can get
rusty (生锈) without constant use. High school and college students, who are
forced to repeatedly exercise their long term memory abilities (at least
long-term enough to get them through a final exam), usually do well on memory
tests. The longer you stay in school, the more chance you get to polish your
learning skills. It’s no wonder that more highly educated people have more
effective memory skills throughout life. 5 Although older people in
general learn somewhat more slowly than they did when younger, a dramatic
difference exists between those who stay intellectually active m reading,
discussing, taking classes, thinking — and those who do not. Giving the brain a
daily workout (锻炼) is just as important as exercising your muscles. Brainwork
keeps your learning strategies in shape, and this helps your memory to function
at full capacity. 6 The next part of a healthy long-term memory is
retention (记忆力), the ability to store what you have learned. Memory researchers
still do not know whether memories are lost—whether they still exist in the
brain but our mental searching cannot turn them up, or have disappeared entirely
as our brain ages. 7 The third necessity for memory is recall, the
ability to bring to mind the memories we have stored. Again, while aging has
widely different effects on the recall abilities of different people, research
indicates that the older we get, the longer it takes to recall facts. But slower
recall is still recall. In fact, aging does not seem to have any effect on
forgetting at all, which takes place at the same rate in younger and older
people. Exercising your brain every day is beneficial______.