雅思分類辭彙：神舟6號和航天

conventional 
traditional, historical, past; accepted, common, regular, routine, mainstream, ordinary

early 
first, old, ancient, primitive, previous, former, remote

simulate 
virtual, create, reproduce, pretend, imitate

artificial 
synthetic, fabricated, contrived, fake, mock, bogus, counterfeit, pseudo

reduce
curtail, cut, decrease, halve, impair, lessen, moderate, trim, slash

future 
what's next, prospect, approaching, expected, destined, forthcoming

worldwide
international, cosmopolitan, global, universal, ubiquitous, widespread, around the world

develop 
evolve, advance, grow, improve, progress, flourish

find
discover, come across, encounter, hit on, expose, notice, note, observe, recognize, spot, uncover

demand
request, claim, need, order, require, call for

decline 
decrease, degeneration, drop, fall, recession, depression, reduction, slump, worsening

significance
importance, milestone, impact, justification, gist, implication, point, purport, vital

prevelant
common, usual, prevailing, widespread, systematic, collective, general, popular

objection
chanllenge, complaint, disapproval, opposition, protest, query, question, remonstration

obstacle 
bar, barricade, barrier, block, blockage, check, obstruction, problem, snag, hurdle

commercial
business, economic, financial, mercantile, profitable, pecuniary

inevitable
unavoidable, certain, destined, fated, inescapable, sure

millitary
armed, belligerent, army, weapon, warlike

role
function (provide, support, weaken, smooth, solve), job, position, duty, post, task, contribution 

recent 
modern, current, now, nowadays, today, contemporaneous, new, novel, present, up-to-date

difficulty 
handicap, hardship, adversity, challenge, complication, dilemma, perplexity, plight, trouble

how
describe, operate, explain, clarify, demonstrate, eludicate, expound, illustrate, interpret, account for