Topic 1: Increasing travels between countries enable people to learn different cultures or to increase tension between people from different countries

 
19.
 
Boost
 
+ 
confidence, economy, image, income, morale, performance, profit, value
 
20.
 
Break
 
+ 
contract, deadlock, habit, law, promise, record, rule, silence, tradition
 
21.
 
Cancel
 
+ 
agreement, appointment, booking, holiday, meeting, trip, visit
 
22.
 
Catch
 
+ 
attention, breath, bus, cold, disease, eye, fire, flight, glimpse, plane, train
 
23.
 
Cause
 
+ 
accident, change, concern, damage, difficulty, harm, loss, pain, problem, 
trouble
 
24.
 
Celebrate
 
+ 
achievement,  anniversary,  birthday,  centenary,  day,  event,  festival, 
holiday, occasion, success, victory, wedding, year 
25.
 
Challenge
 
+ 
authority, claim, decision, idea, notion, view
 
26.
 
Change
 
+ 
attitude, behaviour, direction, face, habit, mind, situation, subject 
27.
 
Collect
 
+ 
data, evidence, information, rent, tax, thought 
28.
 
Combat
 
+ 
crime,  crisis,  disease,  drug,  inflation,  problem,  tragedy,  terrorism, 
violence 
29.
 
Concentrate
  + 
effort, attention, energy, mind, power 
30.