Theory:

For easier explanation of the story, let us divide the story into two parts.
Mani’s family lived in a village near Senji in Villupuram district. Mani liked only a few vegetables. Potatoes and ladies finger were the two that he liked very much. One day, when amma served potato curry...
  
Mani: I don’t want to eat potatoes today, because they are foreign vegetables.
 
Selvi: No, they are not, Amma bought them from the vegetable shop near the bus stop!
 
Mani: Appa, Selvi is too small to understand that potatoes are not from India.
 
Appa: So what?
 
Mani: Our teacher told us that we should buy and eat locally grown food.
 
Selvi: What else did your teacher tell you?
 
Mani: She also told us to use things made in our country.
 
Amma: Then you cannot eat popcorn the next time we go to watch a movie.
 
Appa: And you cannot order tomato soup either, or even pineapple juice.
 
Selvi: Mani, then you can’t order anything.
 
Mani: Why? Why can’t I eat popcorn or soup or... or anything that I want to?
 
Amma: Don’t you know that corn, tomatoes and even ladies finger all came from other countries.
 
Selvi: Really? How did they come to our country Amma? Did they get on an aeroplane and come here?
 
Appa: No, no, Some merchants brought them here long ago by sea.
 
Mani: Why did they bring vegetables to India?
 
Amma and appa laughed.
 
Selvi: They could have brought some sweets. Why didn’t they?
 
Amma: People came to India in search of spices especially black pepper. A man from Portugal named Vasco da Gama sailed to Kerala.
 
Amma: Imagine the joy of the sailors when they reached Kozhikode and found black pepper! They took a lot of pepper back to their country.
 
Selvi: They took spices from India.
Explanation:
  
The story is set as a comic strip style. It is about a family of four members, who are having a conversation over a meal. Mani is a small boy who's family lived in a village near Senji in Villupuram district. Mani addressed his parents as "Amma", "Appa" as known in the regional language Tamil. He also has a younger sister named Selvi. Therefore the characters in this story are Mani, his father (Appa), his mother (Amma), and his sister (Selvi).
 
family1.png
Mani, Amma, Appa and Selvi.
 
Mani did not like all vegetables. He preferred only potatoes and ladies finger. One day when his mom served him potato curry, he stopped her. He declared that he wouldn't eat potatoes because they were foreign vegetables, meaning that it belonged to some other country. His small sister Selvi told him that it was not foreign and that amma had bought the potatoes from the vegetable shop near the bus stop.
 
potatoes.jpg
Potatoes, Mani's favourite!
 
Mani did not reply to his sister and said to his Appa that Selvi was too young to understand that potatoes were not originally from India. His Appa did not understand the point Mani was trying to make. He asked what if potatoes were from foreign countries. Mani explained that his teacher told them that they should buy and eat food crops that were grown locally in our neighbouring cities. Selvi became curious and asked what else his teacher told him. Mani said that his teacher asked them to use things made in India.
 
Hearing all this, Mani's Amma chipped in, and she said Mani could not eat popcorn in the theatre the next time they went to watch a movie. His Appa added that Mani could not order tomato soup or even pineapple juice.
 
soup juice popcorn.jpg
Popcorn, pineapple juice, soup - all are from foreign countries!
 
Selvi took the opportunity to say that Mani cannot order anything hereafter. But Mani was confused, and he asked hesitatingly why he could not order his favourite items.
 
Mani's amma replied that corn, tomatoes and even his favourite ladies finger all had come from other countries. Selvi asked innocently whether the vegetables boarded an aeroplane and came to their country. Appa replied that some people who make business trade brought them to India many years back by ship.
 
sailor.jpg
Some merchants brought the vegetables here long ago by the sea!
  
Mani asked why they brought vegetables to India. Selvi also added that they could have brought some sweets but why didn't they bring. Amma and Appa laughed at their comments.
 
Amma replied that people came to India as they were searching for spices like black pepper. She said that a person from Portugal named Vasco da Gama came by ship to Kerala.
 
vasco-da-gama.jpg
*Vasco da Gama - the Portuguese sailor!
  
They sailed from Portugal to India in search of our black pepper. Amma said they reached Kozhikode and finally found black pepper. They were so happy that they took a lot of black pepper from our country to theirs. Selvi said they took spices from India.
 
black-pepper.jpg
People came to India in search of spices, especially black pepper!
  
Meanings of difficult words:
  
No.
Word
Meanings
1
merchantspeople who trade, especially from foreign countries
2
especiallysingle out one amongst many others
3
sailedtravelled in a ship or boat
4
spicesan aromatic substance, used to flavour food
Reference:
State Council of Educational Research and Training (2019). Term-1 English Standard-6. A Visitor from Distant Lands (pp. 131-144). Published by the Tamil Nadu Textbook and Educational Services Corporation.
*Image courtesy - https://en.wikipedia.org/wiki/Vasco_da_Gama#/media/File:Vasco_da_Gama_-_1838.png