神乐千鹤怎么死的:English choice

Scientists say they are beginning to learn which __B_____ of the brain contain biological clocks.
a. portions
b. parts
c. section
题意说大脑的哪个部分包括生物钟，只有parts表示部分
portion
KK: []
DJ: []
n.
1. (一)部分[C][(+of)]
He left the major portion of his money to the foundation.
他将大部分钱留给了这个基金会。
2. (食物等的)一份,一客[C]
He was hungry and ordered two portions of roast duck.
他很饿,因而叫了两份烤鸭。
3. 一份遗产(或赠予的财产)[C]
4. 命运,定数[U]
We must all accept our portion in life.
我们都得安于天命。
vt.
1. 把...分成多份;分配[(+out)]
She portioned out the cake, so everyone had a piece.
她将蛋糕切成多块,每人可得一份。
2. 给...一份嫁妆(或遗产)
section
KK: []
DJ: []
n.
1. 切下的部分,片,块[C]
Mother cut the cake into six equal sections.
母亲把蛋糕切成相等的六块。
2. (事物的)部分[C]
He occupied the other section of Martin's house.
他占用了马丁房子的另一部分。
3. (文章等的)节;(条文等的)款,项[C]
This chapter has four sections.
这一章有四节。
4. 地区,区域,地段[C]
The mayor inspected the residential section of the city.
市长视察了该市的住宅区。
5. 阶层,界[C]
The government's new economic policy gained acclaim from various sections of society.
政府的新经济政策受到社会各阶层的拥护。
6. 部门;处;科;股;组[C]
7. 【军】分队,小队[C]
8. 断面图,剖面[C]
9. 切开;切断[U]
10. 【生】(指分类单位)派;(果子的)瓣[C]
vt.
1. 把...分成段(或组等)
The teacher sectioned the class for dialogues.
老师把班级分组进行对话练习。
2. 将...切片
vi.
1. 被切割成片(或段)
part
KK: []
DJ: []
n.
1. 一部分,部分[C][U][(+of)]
Parts of the book are interesting.
这本书有几部分很有意思。
2. 部,篇;分册,分辑;节,段;集[C]
That's a radio serial in ten parts.
那是一部十集广播连续剧。
3. 部件,零件[C]
Our workshop turns out parts for generators.
我们车间生产发动机零件。
4. 等分之一,...分之一[C]
5. 本分,职责,作用[S]
If everyone does his part, the project will surely be a success.
如果大家都尽责,这个项目肯定会成功。
6. (争论、交易等中的)一方[U]
7. 角色;台词和动作[C]
What part did you play?
你演什么角色?
8. 【美】(头发的)分线[C]
vt.
1. 使分开,使分离[(+from)]
Her lips were parted in a half smile.
她张开嘴微微一笑。
2. 使分成几部分,使分裂
3. 将(头发)分线
vi.
1. 告别,分手[(+as)]
They parted in London.
他们在伦敦分了手。
2. 分成几部分;断裂
The clouds parted and the sun shone.
云层散开,太阳照耀着。
3. 【口】出钱;付款
ad.
1. 部分地,多少,有些
She was part right.
她有些方面是对的。
a.
1. 部分的,局部的
My parents have part ownership in the restaurant.
我的父母拥有该餐馆的部分产权。

parts
上面那位的解释已经够清楚了