Corrected sentence:
Artificial satellites help us know the weather, send phone and TV signals, and act like tiny labs to study space.
Why this is better (easy steps):
- Capitalize only the first word: start the sentence with a capital letter — "Artificial."
- Add "us" so it reads naturally: "help us know the weather" means satellites help people understand the weather.
- Use a comma before the last item in a list (this makes the sentence clearer): we list three things satellites do.
- Say "tiny labs" to make the idea easy for a child: the satellites are like small laboratories in space where scientists learn new things.
If you want an even shorter version: "Satellites help us know the weather, send phone and TV signals, and study space."