In the following passage there are blanks, each of which has been numbered. For each number, five words are suggested one of which fits the blank appropriately. Find out the appropriate word in each case.

                   Greenhouse gases are only (1) of the story when it comes to global warning. Changes to one part of climate system can (2) additional changes to the way the planet absorbs or reflects energy. These secondary changes are (3) climate feedbacks and they could more than the double the amount of warning caused by carbon dioxide alone. The primary feedbacks are (4) to snow and ice,  water vapour, clouds and the carbon cycle.

                  Perhaps the most well (5) feedback comes from melting snow and ice in the northren hemisphere. Warming temperatures are already (6) a growing percentage of arctic sea ice, exposing dark ocean water during the (7) sunlight of summer. Snow cover on land is also (8) in many areas. In the (9) of snow and ice, these areas go from having bright, sunlight- reflecting surfaces that cool the planet to having dark, sunlight absorbing surfaces that (10) more energy into the earth system and cause more warming.