For anyinformation system to serve its purpose ，the ihformation must be（）when it ìs needed.

A.integralB.availab1eC.irreplaceableD.confidential

A.integral

B.available

C.irreplaceable

D.confidential

A. to describe how pruning a tree is done

B. to discuss different ways of pruning trees

C. to give practical instructions for pruning a tree

D. to explain how a tree wound gets diseased and heals

A．to describe how pruning a tree is done

B．to discuss different ways of pruning trees

C．to give practical instructions for pruning a tree

D．to explain how a tree wound gets diseased and heals

A．To show the way genetic testing works.

B．To indicate the relation between genes and Huntington's disease.

C．To reveal the influence of environmental factors on genes.

D．To introduce genetic testing and its functions.

A．To show how simple the mechanical aids for diving can be.

B．To provide an excuse for his changeable character.

C．To explore the philosophical issues of space travel.

D．To explain why he took up underwater exploration.

A．To give readers some factual information about corporate culture.

B．To criticize managers who try to change corporate culture.

C．To argue against Peter Duckers' opinion.

D．To promote the corporate culture of successful companies.

A．To show his sympathy for those who hasn't got any friends in life.

B．To introduce the topic of the quality and quantity of friends.

C．To disagree with the finding from the research.

D．To show the author's surprise when heating the finding.

A．to suggest several different use of the wire

B．to explain the importance of wire

C．to describe how the wire is made

D．to outline the difficulty of making the wire

A．To try to stop the war in Italy.

B．To help the wounded in the battle.

C．To form. an international treaty.

D．To aid the injured in the earthquake.