Can trees talk? Yes-but not in words.Scientist have reason to believe that trees do ______with each other.Not long ago,researchers learned some ______things.First,a willow tree____in the woods by caterpillars changed to chemistry of its leaves and made them taste so awful that the caterpillars got disgusted and (54) eating them.Then,even more astonishing, the tree sent out special vapors-an (55)signal stimulating its neighbors to change the chemistry of their own leaves and make them (56) tasty.

Communication,of course,doesn't need to be in (57).We can talk to each other by a smile frown,a shrug og out shoulders, a(n) (58) with our hands. We know that birds and animals use a whole vocabulary of songs, sounds, and movements. Bees dance their signals,(59) in certain patterns that tell other bees where to find nectar for honey. So why shouldn't (60) have ways of sending message?

51. A move B touch   C grow  D communicate

52.A surprising  B anxious   C upsetting  D pleasant

53.a eaten B attacked  C consumed  D protected

54.A paused  B delayed   C stopped  D began

55A false  B alarm C traffic D air

56.A less B more  C even  D much 

57.A time   B action  C vocabulary  D words

58.A act B wave C gesture  D movement

59.A telling   B running  C flying  D flowing

60.A animals  B trees C bees  D birds