few decades; many decades; several decades
quick-witted; quick to understand
assistant; helper; assistant (to a professor); research assistant
resemblance; similarity; likeness; analogy
listening device; bug; wiretap
per person; per capita; per head
(slowly and) carefully; without haste; thoroughly; deliberately; closely; meticulously
10,000,000,000; ten billion
maintenance; servicing; putting in place; development; improvement
full version; complete version; unabridged edition
on the way; as one goes; in the future; someday; eventually
range of use; range of application; range of applications; scope (of a document)
immediate (effect, result, etc.); instant; instantaneous; prompt
in deep black; in jet black
starting (a machine, engine, etc.); starting (a project, plan, etc.); beginning; initiation
having little knowledge (of); being ill-informed
to wet oneself; to be miserly; to be stingy
planned; scheduled; systematic
to get fed up with; to get sick of; to become disgusted with
autopsy; post-mortem (examination); (coroner's) inquest; examination of a body to determine if a crime has been committed
public peace; public safety; public security; security police
extremists; radicals; militants
exposing; unmasking; laying bare
one's post; one's station; department; bureau; section
search (esp. in criminal investigations); investigation; inquiry; enquiry
retirement (from work); leading a quiet life (after retirement); retired person; retiree; surrendering headship of the family (pre-WWII)
spy; agent provocateur; covert operative; maker; builder; constructor
imitation; copy; make-believe; doing something in a way that only superficially resembles the real thing
retiring from military service
secret meeting; clandestine meeting
sentimental; mushy; saccharine; sickly-sweet; sugary