自从美国回来，有很多学生找我解答托福上的一些问题，其中有很多同学说记不住单词或者学校给的单词太多，很难记住。我花费了一些时间，总结整理出托福考试最精华的400个单词，分40个类别，我先放9类90个单词，如果觉得好，继续整理后面的31类放上来，请评论回复。

Group 1  food crops

1.abandon                         

2.adversely

3.aggregate

4.cultivation

5.fertilize

6.intensify                          

7.irrigation                                     

8.obtain                              

9.photosynthesis                               

10.precipitation 

Group 2   disaster

1.anticipate

2.catastrophic

3.collide

4.eruption

5.famine

6.flood

7.impact

8.persevere

9.plunge

10.unleash

Group 3   evolution and migration

1.adapt

2.diverse

3.evolve

4.feature

5.generation

6.inherent

7.migration

8.physical

9.process

10survive

Group 4   petroleum alternative

1.constraint

2.contamination

3.deplete

4.dispose of

5.elementally

6.emission

7.extinction

8.reservoir

9.shrink

10.stable

Group 5   time efficiency

1.adjust

2.arbitrary

3.denominator

4.exponentially

5.infinitesimal

6.maximize

7.parallel

8.proportion

9.rate

10.sequence

Group 6   ancient life

1.accuracy

2.adjacent

3.compress

4.feasibly

5.gut

6.integrally

7.overlap

8.retain

9.seep

10.structure

Group 7   computers

1.circulate

2.corrode

3.derive

4.detection

5.expeditiously

6.implement

7.innovative

8.installation

9.maintenance

10.simulation

Group 8   energy

1.combustion

2.component

3.convey

4.discretely

5.nucleus

6.permeate

7.rotate

8.solar

9.source

10.trigger

Group 9    memory

1.acquisition

2.anomaly

3.consciously

4.degrade

5.gap

6.indisputable

7.intervene

8.intuitively

9.recede

10.retrieve

这个帖子好，请楼主继续把剩余的31个类别的单词整理一下吧。

看前人的总结经验，比自己辛苦搞来的简单有效率多了。