She has a theory that drinking milk prevents colds.是什么意思？

She has a theory that drinking milk prevents colds.

她有一种说法,认为喝牛奶能防止感冒.

she

pron. 她，它；

例句
Her lover walked out on her after she had aborted their child.
她的情人在她打掉胎儿后甩了她。

has

v. 有( have的第三人称单数 )，（亲属关系中）接受，拿，买到；

例句
...the operation a patient has had.
病人做过的手术

theory

n. 学说，理论，原理，推测；

例句
...a theory that is steadily gaining acceptance...
逐步得到承认的理论

that

det. 那个，那；pron. 那个，那；conj. 多么，如此…以至，用于某些动词、形容词和名词后，引出各种从句；adv. 不那么，那样；

例句
...expensive make-up that we saw being advertised by a beautiful model...
我们所见的由一位漂亮模特代言的昂贵化妆品

drinking

n. 喝饮料，喝酒；v. 喝（酒）( drink的现在分词 )，饮，喝酒，（尤指）酗酒；

例句
Wine is radioactive but few people stop drinking it on that account.
酒是有放射性的，可是很少有人因此而戒酒。

milk

n. 奶，乳液，母乳；vt. 挤奶，榨取；

例句
Soya milk can cause allergic reactions in some children.
有些孩子会对豆浆过敏。

prevents

v. 预防( prevent的第三人称单数 )，阻碍，阻止，[宗教]引领；

例句
The camera has a built-in failsafe device which prevents it from working if the right signals aren't received.
照相机有内置自动防故障装置，该装置确保相机在未接到正确信号时不会启动。

colds

n. 冷( cold的名词复数 )，寒冷，伤风，感冒；

例句
Eating oranges keeps colds at bay...
吃橘子可以预防感冒。