The composition "A Useful Thing" is 450 words.

One morning, the sun was shining brightly. After breakfast, I heard the weather forecast that there would be a thunderstorm that night, so I went to school happily with an umbrella and a bag on my back.

When school is over at night, the weather is getting cloudy and heavy, and I feel that a heavy rain is coming soon. Xiaohong and Xiaoming and I hurried home, but when we were halfway there, there was a strong wind, lightning and thunder, and the wind came like Ma Benteng, and lightning and thunder seemed to break the earth. In a blink of an eye, raindrops the size of soybeans swept in, splashing white flowers on the ground.

At this time, Xiaohong and Xiaoming want to run under the tree to avoid the rain. I said to them, "it's too dangerous to shelter from the rain under the tree when it thunders." I have an umbrella here. Let me take you both home. " So, the three of us continued to walk home with umbrellas. Because the umbrella is small, I tried to cover them both with an umbrella, so that my back was quickly wet by the rain. I'll take Xiaoming home first, and then Xiaohong home.

When I got home, my clothes were almost soaked. My mother saw me like this and asked reproachfully, "Didn't you bring an umbrella today?" ! "I told my mother what happened. My mother praised me for doing the right thing and said that I was a good boy who helped others.