Hello, Sophia! It is nice to know that you have done your homework finally! Please study about these explanations...

    ************CORRECTED ESSAY OF SOPHIA LEE**************

 I will tell you about my unforgettable trip.
When I was 13 years old, I went on a trip to Dal-gung Valley in Jiri Mountain with my whole family. At that place, my sister and I played with our very close cousin, and we ate many delicious food (In my case pork was the most delicious).
We chatted for a long time and we slept together. Though it was hard to go there (because Dal- gung Valley is far from my house and it's on the top? of the mountain), everybody enjoyed the trip. So, I want to go there with them again and I think I can't forget about it.

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Wow, Sophia! I just made some minor corrections. Please check thse corrections out...

1.
SOPHIA: When I was 13years old, I went on a trip to dal-gung valley in jiri mountain with all of my family.
CORRECT: When I was 13 years old, I went on a trip to Dal-gung Valley in Jiri Mountain with my whole family.

>> Please be careful with the spaces. Put a space to separate "13" and "years old."

>> Capitalize the first letters of proper nouns. --> Dal-gung Valley / Jiri Mountains

>> In some cases, "all of my family" is acceptable. However, for the sake of more commonly used, let's say "my whole family." "all of my family" could mean that you have a lot of family.

>> Don't forget to put a space after the period <.>

2.
SOPHIA: At that place me and my sister played with our very close cousin, and we ate many delicious food. (In my case pork was the most delicious)
CORRECT: At that place, my sister and I played with our very close cousin, and we ate many delicious food (In my case pork was the most delicious).

>> When we are putting the setting (time or place) at the beginning of our sentences, put a comma <,> after it. -->> At that place,

>> Study about the difference between "I" and "me." You may use "I" when you are the subject of the verb. You may use "me" when you are the object of the verb.

>> We may delete the pronoun "we" because it is already understood.

>> Since the statement in the parentheses supports the first clause, we may place the comma <,> after it.

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There you go, Sophia. I am really mesmerized by your work. I hope you keep this up or should I say improve even more because you're already making it!

Teacher Ace~