complicated; complex; intricate; confusing; difficult; troublesome
alone; by oneself; on one's own
(some) more; even more; longer; further
countries; (various) nations
to prosper; to flourish; to thrive; to become popular; to become widespread
archeologist; archaeologist
research; study; investigation
example; instance; precedent; custom; habit
remainder; remnant; (not) very; (not) much; too much; excessively; extreme
marine pollution; oceanic pollution; sea pollution
end; extremity; limit; result; outcome; upshot
(on) land; ground; shore; track and field; athletics
to destroy; to overthrow; to wreck; to ruin
stage (of a theatre, concert hall, etc.); stage performance; stage production; setting (of a story); scene; sphere (of activity)
roughly; approximately; (cutting) in one stroke; (breaking apart) with vigour; (cutting) deeply; (splitting) wide open
destructive; catastrophic; disastrous; ruinous; devastating
favourable; favorable; doing well; OK; all right
Middle Ages (in Japan esp. the Kamakura and Muromachi periods); medieval times; mediaeval times
level; standard; level (amount or quantity); level (plane); level (instrument); spirit level
retreat; falling back; recession; waning; backspace (key)
large; big; great; prominent; -sized; as big as; university
extinction (e.g. of a family); dying out; discontinuation; severance (e.g. of relations); rupture; breaking off
catastrophe; cataclysm; collapse (of a relationship); breakup; split (friends, lovers, etc.)
decline; degeneration; decay; waning; ebbing
nature; natural; spontaneous; naturally; spontaneously
return (to); revolution; recurrence; regression
possible; conceivable; likely; probable
the past; bygone days; one's past (that one would prefer remained secret); past (tense); preterit; previous life
historical; traditional; historic
to spread (of a rumour, news, etc.); to travel; to be handed down (from generation to generation); to be passed down; to be introduced (to a country, region, etc.); to be brought; to be conveyed (of a feeling, impression, etc.)
complete; whole; perfect; safe
when it comes to ...; where ... is concerned; if it's the case that ...; if it turns out that ...; if it's true that ...
to go to ruin; to go under; to fall; to be destroyed; to die out; to become extinct
calm; quiet; gentle; moderate; reasonable; amicable
one; 1; best; first; foremost; beginning; start
noon; midday; daytime; lunch
still; yet; more; still more; furthermore; in addition
room; chamber; apartment; flat; stable
two persons; two people; pair; couple