Theory:

BANG!
What's that?
Bang-Bang! Oh, Hark,
The guns are shooting in the dark!
Little guns and big ones too,
Bang–bang-bang!
What shall I do?
Mistress, Master, hear me yelp,
I'm out-of-doors, I want your help.
Let me in-oh, LET ME IN
Before those fireworks begin
To shoot again-I can't bear that;
My tail is down, my ears are flat,
I'm trembling here outside the door,
Oh, don't you love me anymore?
Explanation:
  
This poem is set on a firework night in the United Kingdom. It is a night where fireworks are burst and celebrated by the whole nation. Colourful bright displays with banging sounds are filled all over the country on such days. Enid Blyton wrote this poem.
  
fireworks.jpg
Fireworks in full display!
  
The poem is narrated by a pet dog that gets frightened due to the noise of the fireworks. He heard the loud BANG! sound and wondered what the sound was. He again heard the sharp, loud banging noise. He asked his master to listen if he's also able to hear the same. The poor dog thought it was the sound of someone shooting from their guns in the night time. He thought the smaller fireworks were shooting with little guns and the bigger fireworks were from bigger guns. He was very scared and wondered what to do.
 
firework dog.jpg
The poor dog wondered if the fireworks were gunshots!
 
He called to his master and mistress. He asked them if they heard his cries of alarm. He thought he was in danger. He asked his master and mistress for their help. He wanted them to let him in. He pleaded that he was outside and he wanted to come inside, into the safety of the house. He said before the next firework began he wanted to come in. He said if they shot again with the gun, he cannot bear it. Already his tail had gone down in fright, and his sharp ears had become flat. He was shivering with fright outside the door. He asked his master if they did not like him, as he was suffering outside, and they were sitting inside without taking care of him. He wanted to go inside the house somehow. He tried his best to convince his master.
 
Meanings of difficult words:
 
No.
Words
Meanings
1
banga sudden loud, sharp noise
2
yelpa short, sharp cry, especially of pain or alarm
3
harklisten
4
tremblingshaking or shivering due to fright or anxiety
Reference:
State Council of Educational Research and Training (2019). Term-1 English Standard-8. Firework Night(pp. 141-144). Published by the Tamil Nadu Textbook and Educational Services Corporation.