is a thing of the past B. has not yet been achieved
is there for those who merit it D. has greatly improved our society
Movie directors use music to ________ the action on the screen.
A) contaminate B) compliment C) contemplate D) complement
A new study on birds’ sleep has revealed that ________.
A) half brain sleep is found in a wide variety of birds
B) half brain sleep is characterized by slow brain waves
C) birds can control their half brain sleep consciously
D) birds seldom sleep with the whole of their brain at rest
