Hello there Aloa,

Thank you for submitting your homework. I'm so happy because in spite of being busy in school you still manages to submit your homework on time. please take note of my corrections and see you in our class. Thank you..^_^

Animals are one of the valable life.

Correct: Animals are one of the important ones.

** I rephrased some of the words to easily understand your sentence.

Pets, too.

**Pets are animals too, so you don't need to include this one.

Sine we can think, we have to take care of them hard.

Correct:Since we are human, we have to take care of them well.

** I rephrased some of the words to easily understand your sentence.

** Use "well" to mean "in a good, proper, satisfactory manner, or to a high standard" instead of "hard".

We need to protect them very carefully.

Correct: We need to protect them carefully.