exasperate

cataclysmic

trenchant

antibody

elicit

substantial

arbitration

antidote

pathogen

extraneous

clandestine

rebut

procurement

ambivalent

acid rain

sterilize

biosphere

prenatal diagnosis

smallpox

inhibit

inject

bedrock

reliable

intervention

narcotic

penetrate

avert

coexist

tenure

deleterious

drought

scrape

opium

fertile

propagate

counterproductive

jeopardy

addict

degrade

dioxin