arduously, strenuously, hard #easily

(a)  

origin, derivation, foundation

(a)  

someone's family, education, previous work etc

(a)  

meet, come across, bump into

(a)  

quite, rather, comparatively

(a)  

hard or firm, with a fixed shape, and not a liquid or gas

(a)  

outside, facade, exterior

(a)  

restrict, restrain, limit, keep

(a)  

if an event, accident, illness etc leaves you in a particular condition, you are in that condition because of it

(a)  

related, linked, connected

(a)  

previous, earlier, preceding

(a)  

age, period, time

(a)  

period during which sth is very successful, especially in the past

(a)  

in a way that makes it seem that something is true or that something is happening

(a)  

top, climax #dip

(a)  

in some way, or by some means, although you do not know how

(a)  

microorganisms, microbes, germs

(a)  

barely, hardly #fully

(a)  

to discover or show information about something, especially about its shape or arrangement, or how it moves or works

(a)  

the bottom of a sea or ocean

(a)  

the way that an organization, machine or organism operates

(a)  

describe, state, explain

(a)  

call, name, label

(a)  

in a way that relates to science, or uses the methods of science

(a)  

famous, outstanding, well-known

(a)  

hiker, climber, walker, rock climber in the act of doing sth=at the moment that you are doing something

(a)  

activist, supporter, promoter

(a)  

instead of someone, or as their representative

(a)  

used to show that something or someone is usually called a particular name

(a)  

ethnic, clannish

(a)  

far, remote, distant

(a)  

traverse, go across, cross over

(a)  

not performed with machines or involving machines

(a)  

a large desert animal with a long neck and either one or two humps (=large raised parts) on its back

(a)  

something that is done to attract people's attention, especially in advertising or politics

(a)  

to start to use something again that was used in the past

(a)  

irrespective of, despite, no matter, in spite of, apart from #considering

(a)  

the process of learning about yourself and your beliefs

(a)  

explanation, description, meaning

(a)  

marginally, vaguely #considerably

(a)  

reveal, indicate, signal

(a)  

attempt, effort, try

(a)  

innovator, inventor, developer, discoverer

(a)  

famous, well-known, important, outstanding, renowned #obscure

(a)  

someone who studies history, or the history of a particular thing

(a)  

leading-edge, front-line, pioneering, innovative, radical #old-fashioned

(a)  

someone who works or is trained in science and so on/forth=used at the end of a list to show that you could continue it in a similar way

(a)  

standards, principles, measures, norms

(a)  

method, tactic, attitude

(a)  

sure, certain, fixed #uncertain, unsure

(a)  

object, purpose, aim, point, goal, intention

(a)  

from the beginning

(a)  

the information that someone has discovered as a result of their study, work etc

(a)  

state, announce, assert, say publicly

(a)  

prejudice, partiality, favoritism, predisposition, preference #impartiality

(a)  

voyage, excursion, trip, journey

(a)  

sole, exclusive, exceptional, distinctive #common

(a)  

remote, lonely, cut off

(a)  

referred to lost tribes, are communities who live, or have lived without significant contact with global civilization

(a)  

viewpoint, attitude, perspective

(a)  

progress, move ahead, go on

(a)  

mainland, inland, interior, central, main land

(a)  

relating to a large mass of land

(a)  

the most northern or most southern point on a planet, especially the earth

(a)  

bug, germ, bacteria, microorganism

(a)  

if an animal grazes, or if you graze it, it eats grass that is growing

(a)  

besides, apart from, except for

(a)  

under the earth's surface

(a)  

expert, professional

(a)  

ignore, discount, forget

(a)  

communicate, send, pass on, express

(a)  

good or interesting because it has not been done, seen etc before

(a)  

clarification, understanding, explanation

(a)  

way, road, path

(a)  

vision, perception, awareness

(a)