高中英语78阅读短文Movement is medicine for the mind:here’s how your

高中英语78
阅读短文
Movement is medicine for the mind:here’s how your mental
muscle benefits every time you get going.
1.It
stimulates brain growth
As we get older ,the birth of new brain cells
slows,and our brain tissue actually shrinks.Exercise may be able to reduce
that trend.One brain-scanning study of healthy people aged 60 to 79 showed
significant increases in brain volume after six months of fitness training.
2.It
boosts brain-building hormones
Much like plant food makes plants grow faster
,the chemical known as BDNF ,stimulates the growth of brain cells.This is
especially true in the hippocampus ,the brain region that is largely
responsible for memory and which is particularly easy to age-related
decline.The more you exercise ,the more BDNF you produce.
3.It
fights depression and anxiety
Depression
slows the brain’s ability to process information ,makes it more difficult for
us to concentrate and reach decisions,and causes real memory problems.For
milder cases,exercise may help lift your mood.And it boosts levels of the
feel-good chemicals called endorphins.
4.It reduces the
effects of stress
If some hormones
like BDNF make the brain younger,others help age it.These include the
so-called stress hormone cortisol.Exercise lowers cortisol levels ,helping you
to think straight again.It is also believed to help generate new nerve cells
in the area of the brain called the dentate gyrus .Brain cells
here_________during times of stress.
5.It improves your brain’s executive function
Executive function basically means abilities like being
able to focus on complex tasks,to organize,to think abstractly ,and to plan for
future events.It also includes working memory,such as the ability to keep a
phone number in your head while you dial.When researchers set out to analyze
the effects of exercise on executive function,they looked at 18 well-designed
studies and found that adults aged 55 to 80 who did regular exercise performed
four times better on cognitive tests than control groups who didn’t work out.
78.Fill in the blank in the passage with proper words.(no
more than 2 words)
正确答案是:are reduced,我的答案是：increase,请具体解析为什么我的答案不对?

Brain cells here_________during times of stress.
首先要确定肯定是用复数（主语：Cells） 这句话理解为 在紧张的时候,这一部分脑细胞会?根据这一段的段意来看紧张时应该是会减少你的脑细胞使你思维变慢,所以才说锻炼可以抑制这种情况