一、文章主旨：
根据首句，我们可以看到整篇文章的主旨意思：physical activity does the body good, and there’s growing evidence that it helps the brain too.（身体活动对身体活动有好处，越来越多的证据显示它对大脑也有好处），所以我们可以知道整篇文章实际是在讨论身体活动与大脑活动相关的影响。
二、对15个选项进行词性分类
A.n
B.adv
C.n
D.v-ing
E.v-ing
F.adj
G.adj
H.v
I.n
J.adv
K.adv
L.n
M.v
N.v
O.v
三、判断空格词性
26. , ___ to have higher GPAs and better scores 固定搭配 tend to 倾向于
答案：O
27. In a ___ of 14 studies that 空格词性为名词 ，备选项有 ACIL A. 出席，出勤 C 趋势 I 心境 L 表现
答案：C
28. physical activity and academic ___ 空格词性为名词，备选项有 A I L
答案：A
29. , ___ in the basic subjects of math, 空格词性为副词，备选项有BJK
答案：K
30. schools struggle to ___ on smaller budgets. 空格词性为动词原形 备选项有HMN
答案：N
31. With standardized test scores in the U.S. ___ in recent years, 空格词性为动词ing，备选项有DE
答案：E
32. exercise and academics may not be ___ exclusive. 空格词性为副词，备选项有BJ
答案：J
33. can improve blood ___ to the brain 空格词性为动词 备选项有 DHM
答案：H
34. ，which are ___ to learning. 空格词性为形容词 备选项有FG
答案：F
35. can improve ___ and relieve stress. 空格词性为名词，备选项有IL
答案：L