Theory:

      One day there was a quarrel between Vetri and Asif’s families, and both families stopped talking to each other. To everyone's surprise they continued to be good friends. There was always a healthy competition between them. Surprisingly the exam, the results and the marks never affected their friendship. Their friendship continued till tenth standard. Then Vetri moved to Coimbatore and Asif to Chennai. Asif started his business in Chennai and settled there. Vetri always wanted to meet his friend but never had the chance to visit Chennai.

Explanation:
 
One day, there was an argument between the families of Vetri and Asif. Both the families stopped talking to each other, but Asif and Vetri did not care about it. They continued to be good friends. Everybody was surprised that their friendship was not disturbed by their parents' fight. There was competition between them, but it was productive - both of them improved without pulling down/defeating the other. No factor could change the friendship between them - not even their marks, exams or results. But their friendship continued only till tenth standard. Their families moved to different places - Vetri moved to Coimbatore and Asif moved to Chennai. Later Asif started his business in Chennai and settled down there itself. Vetri settled in Coimbatore. He always wanted to meet his friend Asif, but he never got the opportunity to visit Chennai.
 
Meanings of difficult words:
 
No.
Words
Meanings
1
quarrela heated argument or disagreement
2
healthy competitionproductive improvement for all competitors
3
affectedcause a change to someone or something
Reference:
State Council of Educational Research and Training (2019). Term-1 English Standard-8. Friendship(pp. 104-118). Published by the Tamil Nadu Textbook and Educational Services Corporation.