How should I write a composition?

My wish composition is 400 words.

A wish is like a seed, buried in the soil of the "heart". Although small, it can take root and sprout. Everyone has a wish buried in his heart.

My wish is to become a scientist, especially to see tall trees being ruthlessly cut down, clear rivers being seriously polluted, and the resources that the earth has dedicated to mankind being madly wasted. I really want to be a scientist and invent an instrument to revive the cut trees and make the polluted rivers crystal clear.

Since childhood, scientists have a sacred position in my heart. I am surprised at the inventions of those scientists. I really admire those scientists who can invent such amazing things, bring people such a comfortable life and bring people endless convenience and speed. Therefore, becoming a scientist is more determined in my heart.

What I admire more is the scientist's spirit and hard-working clock psychology. When Edison invented lighting, he used thousands of materials and failed, but he was not discouraged. He rallied from failure and finally won. When he invented the new battery, he suffered fifty thousand failures. His assistants wavered, but he kept trying and finally succeeded. When Madame Curie refined radium, she was only in a broken straw shed. However, she was not intimidated by this difficulty. On the rugged road of science, she always climbed tenaciously and finally reached the glorious peak. I deeply admire the indomitable spirit of scientists who are not afraid of difficult environment.

I hope this seed is still small, but it will blossom and bear fruit one day.