Andrew: I always eat foods because of life and use my cell phone for sending messages.
Correct: I always eat food to survive. I also use my cell phone for sending messages.
Explanation: The preposition "to" is used for expressing aim, purpose, or intention.

Andrew: My parents are supportive to me. So, I always help my parents anything.
Correct: My parents are supportive so I always help them.
Explanation:The pronoun "them" is 1.used as the object of a verb or preposition to refer to two or more people or things previously mentioned or easily identified.

Andrew: I always have to thanks for giving anything.
Correct: I always thank them for everything.
Explanation: The pronoun "them" is 1.used as the object of a verb or preposition to refer to two or more people or things previously mentioned or easily identified.

Andrew:In our country, many parents seem to be supportive to their son or daughter
Correct: In our country, many parents are supportive. It's because they love their children.

Andrew: I'd like to be supportive when my parents are old. So, I'll need to be responsible.
Correct: In return, I would like to take care of my parents when they get old. I need to be responsible.

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Hi, Andrew! Thank you for submitting your homework. I could see that you totally love your parents. Just like you, I also want to take care of my parents when they old. Anyway, keep up the good work, Andrew! See you tomorrow.

-Teacher Isabel