1. I get rid of the trash.
2. I turn on the computer.
3. I can't stand this person.
4. I lose it when playing with my friends.

==============================

1.
Alice: I get rid the trash.
Correct: I get rid of the trash.
Explanation:
*get rid of something (idiom)
get rid of + something
get rid of + the trash

2.
Alice: I turn on the comeputer.
Correct: I turn on the computer.
Explanation:
*Spelling
Please be careful with the spelling of the word "computer".

3.
Alice: I can't stand with this person.    (meaning: I cannot stand next to him/her.)
Correct: I can't stand this person.        (meaning: I don't like him/her.)
Explanation:
*The phrase can't stand with means you cannot get near or stand next to him/her.

4.
Alice: I lose it playing with my friends.
Correct: I lose it when playing with my friends.
Explanation:
*When is used to indicate at what time.

==============================