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