I thought I saw a dead body,but then I realized it wasn't a body. Now I don't know what I should have done.
Why did you think it was a dead body?
She looked dead, but when I got closer I realised she was still alive.
If you saw someone who looked dead at first, it is a good idea to stop and see if they need help. Someone who is injured shouldn't be left alone. You should help people who are in need of it, if you are able to.
I really thought she was dead.
I know you thought this person was already dead, and it's a scary situation, but you should always make sure if they are dead or alive. That way, if they are alive you can call for help.