IV. Supply the correct forms of the given words. 16. On __________ in Hanoi, I was picked up by my pen pal. (ARRIVE) 17. What have the authorities done to improve public __________ of the city? (TRANSPORT) 18. Life in __________ advanced countries are more comfortable. (TECHNOLOGY) 19. My __________ boys can’t stand staying in the whole weekends. (ENERGY) 20. We were not satisfied with the service. The sales assistants were __________. ( HELP)