enclosing wall; boundary fence; obstacle; barrier
to come down; to go down; to hang; to dangle; to move back; to step back; to deteriorate
intruder; invader; trespasser; raider
scaffold; scaffolding; foothold; footing; foothold (e.g. in business); foundation
once; one time; temporarily; for a moment; one degree; one tone
unlimited; unrestricted; limitless
independence; self-reliance; independence (e.g. of a nation); freedom; separation; isolation
fossil; petrifaction; petrification; fossilization
footprints; record of page visitors (e.g. in social networking sites)
clear; precise; definite; distinct
to follow (road); to pursue (course); to follow up; to follow (hyperlink)
evolutionary theory; theory of evolution
filtration; filtering; percolation
single cell; simple-minded person; one-track-minded person
metabolism; renewal; regeneration; replacing the old with the new
actually; really; truly; in practice; practically
astonishing; amazing; surprising; wonderful
adaptability; flexibility
fast; quick; early (in the day, etc.); premature; (too) soon; not yet
alternation; change; relief; relay; shift; substitution (sports, etc.)
several; a number of; quantity; amount; counting; figures; number
good; excellent; sufficient; enough; profitable (deal, business offer, etc.); beneficial
diagnosis; medical examination
to be troubled; to have difficulty; to be bothered; to be inconvenienced; to be badly off; to be hard up
weak; frail; delicate; tender; unskilled; weak (wine)
toxicity; virulence; toxic; virulent; poisonous
to put back; to return; to vomit; to throw up; to recover (of a market price)
two directions; both directions; two-way; bidirectional
examination; exam; test; trial; experiment; test
within the jurisdiction of
as one expects; as one wants; to one's satisfaction; as one sees fit
correlation; interrelation
to get into an argument; to come to discuss; to be controversial (usu. as an adjectival phrase); to be contentious
textbook; coursebook; schoolbook