Can trees talk？ Yes， but not in words． Scientists have found that trees can communicate with each other． Not long ago， scientists found some surprising things． A willow tree（柳树） was attacked（被侵袭） by caterpillars（毛毛虫）． At first it changed the chemistry of its leaves and made them taste so terrible that the caterpillars got tired of the leaves and stopped eating them． Then even more surprising， the tree sent out a special smell-a signal（信号） causing its neighbours to change the chemistry of their own leaves and make them less delicious．
Communication， of course， doesn't need to be in words． We can talk to each other by smiling， raising our shoulders and moving our hands． We know that birds and animals use a whole vocabulary of songs， sounds， and movements． Bees dance their signals， flying in certain ways that tell other bees where to find flowers for honey． So why shouldn't trees have ways of sending messages？



We can know from the passage that caterpillars do not feed on leaves that． ______

A. have a terrible taste
B. are lying on the ground
C. have a strange shape
D. bees don't like

What will the willow tree in the passage do to protect itself？ It will ______ ．

A. grow more branches
B. change the chemistry of its leaves
C. communicate with birds and bees
D. shake caterpillars off

According to the passage， the willow tree was able to communicate with other trees by ______ ．

A. shaking its branches
B. sending out a special smell
C. dropping its leaves
D. changing the colour of its leaves

How can bees communicate with their partners？ ______

A. By touching one another．
B. By smelling one another
C. By making special movements．
D. By making unusual sounds．

The happening in the passage ______ ．

A. cannot be considered carefully
B. seems rather reasonable（合情合理的）
C. should no longer be allowed
D. will not happen any more