Fill in the blanks for the passage below with the correct word.

As the temperature (1)--------------- during the summer season, many households turn to air conditioners to keep them cool. Air conditioners, which were once regarded as a residential luxury, have now become a (2)--------------. Enjoying a cooler atmosphere during hot weather is not the only benefit of using the air conditioner. A household, a vehicle, or a building becomes cleaner and safer for breathing as air conditioning also (3)---------------- the growth and spread of harmful micro-organisms. However, along with the benefits, some disadvantages are also (4)---------------- with it. One of the most controversial topics attached to the subject of air conditioning deals with some of the materials that are used to produce the cooling effect —fluorocarbons. These refrigerants (5)---------------- to global warming and are (6)--------------- as one of the main ways in which air-conditioning (7)----------- the environment. Fluorocarbon refrigerants also add to the problems concerning ozone layer depletion.

While air conditioning provides temporary relief and makes heatwave like conditions a bit more bearable, many questions have been (8)-------------- on how much the world will pay in the long run in terms of the environmental damage that it has caused.