Humans increase the amount of carbon dioxide released to the atmosphere when they
  burn fossil fuels, solid wastes, and wood and wood products to heat buildings, drive
  vehicles, and __1__ electricity. At the same time, the number of trees available to
  absorb carbon dioxide __2__ photosynthesis has been __3__ reduced by
  deforestation, the long-term __4__ of forests by thoughtless cutting of trees for lumber
  or to __5__ land for agricultural activities.
  
  1.
   A) reflect
   B) lean
   C) evaluate
   D) generate
  2.
   A) with
   B) through
   C) to
   D) as
  3.
   A) usefully
   B) greatly
   C) uselessly
   D) mildly
  4.
   A) enhancement
   B) environment
   C) treatment
   D) destruction
  5.
   A) clear
   B) produce
   C) stop
   D) radiate

  When the global temperature is stable, the atmosphere eventually transfers all this energy
  back into space; if it did not, the total amount of heat on the earth's surface would __1__
  be increasing. Because of the many layers of water vapor and other molecules __2__ in
  the atmosphere, the heat is transferred out __3__ the upper atmosphere slowly. Even
  when __4__ temperature is stable, the delay in heat transfer __5__ the total amount of
  heat present on the earth's surface at any given time.
  
  1.
   A) exactly
   B) particularly
   C) constantly
   D) occasionally
  2.
   A) present
   B) polluted
   C) destructive
   D) wonderful
  3.
   A) through
   B) with
   C) by
   D) at
  4.
   A) excess
   B) particular
   C) straight
   D) global
  5.
   A) raising
   B) raises
   C) raised
   D) raise