【简答题】

    We often think of insects as be harmful.       
This is partly true. Many insect are harmful       
Flies carry diseases. Others insects carry diseases,       
too. Farmers are at war with insects most       
the time.  Hunger insects kill crops in the fields.       
Farmers spray the field get rid of these insects.       
Does this mean that all insects are harmful? No.       
Many are of great helpful to man. Bees make        
honey. With bees and other insects, many trees        
would have not fruit. Silkworms make silk. Some    
insects eat other insects that kill fruit trees.