Theory:

As wind falls.
When string goes slack
You wind it back
And run until
A new breeze blows
And its wings fill
And up it goes!
How bright on the blue
Is a kite when it’s new!
But a raggeder thing
You never will see
When it flaps on a string
In the top of a tree.
Explanation:
 
As the wind falls, the string of the kite gets loose. So, they will bring the string back and will again run with it until there is another breeze.
 
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A girl running with her kite

Once the breeze starts, the kite will be blown back into the sky. So, the colourful kite will once again be soaring beautifully in the blue sky.
 
But, all of a sudden, when the string is cut off, the kite will drop itself on a tree.
 
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A kite stuck on a tree
 
As a result, the kite will get torn as the kite is made of paper.
 
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A torn kite
 
Meanings of difficult words:
 
Sl.No
Word
Meanings
1.
SlackLoosely hanging
2.
Raggeder Worn out
3.
String Thread
4.
Breeze A gentle wind
5.
FallsDrop down
6.
Flaps Flutter
Reference:
National Council of Educational Research and Training (2006). Honeysuckle. The Kite  (pp. 27). Published at the Publication Division by the Secretary, National Council of Educational Research and Training, Sri Aurobindo Marg, New Delhi.