Theory:

     “Hi Fatima, isn’t this fun?” I called out as my friend came into the compartment. “Come, sit here. I have kept a seat for you. You can keep your bag next to mine. What have you brought to eat?” “Parotta and delicious chutney. Did you see the train? It’s so beautiful!” Fatima replied.
 
     Our teacher, Geetha madam, came around to see if everyone was seated properly. “The train is about to leave so take your seats everyone,” she said. Just then the train started with a jerk. It moved very slowly, leaving the station with a long hoot. Everyone clapped. The train went snaking up the steep hillside, weaving its way through forests of tall trees swaying in the breeze.
 
     One of the boys, Muthu, said, “It is going so slowly, I can walk along its side.” And he got up to go to the door.
 
     From the other end the teacher saw him and said in a firm voice, “Muthu, go back to your seat at once.” The girls sniggered and Muthu sat down with a long face.
Explanation:
 
Just then Merlin's friend Fatima entered the compartment. Merlin asked her friend if she was enjoying the fun too. Merlin reserved a seat for her friend near her, and she told her to put her bag near hers. She asked her what she had brought to eat, to which Fatima replied that she had parottas, a layered bread along with some tasty chutney. She was also excited about the train and exclaimed that it was beautiful.
 
Their teacher, Geetha Madam, just came by to see if everyone had sat down in their seats. She announced that the train was about to leave and that everyone should settle down soon. Just then, the train started with a quick, sharp pull. The train moved slowly out of the station with a low screeching sound. All the children clapped in excitement. The train moved like a snake, slowly because it was a steep hillside, making its way inside the thick forests, filled with tall trees swinging in the breeze.
 
Muthu, one of her classmates, commented that the train was going so slow that he could walk side by side with the train. He meant the train moved only at the speed of a walking person. He stood up and walked towards the train door. But their teacher caught him soon enough and told him firmly to go back to his seat. The girls laughed in a suppressed tone, in a teasing way. Muthu had a disappointed expression in his face.
 
Meanings of difficult words:
  
No.
Words
Meanings
1
hoota screeching sound
2
snakingmove like a snake
3
swayingto move slowly or rhythmically backwards and forwards or from side to side
4
sniggeredlaugh in a half-suppressed, teasing manner
5
long facean unhappy or disappointed expression
Reference:
State Council of Educational Research and Training (2019). Term-2 English Standard-6. Trip to Ooty (pp. 111-127). Published by the Tamil Nadu Textbook and Educational Services Corporation.