The class of Biology

Hello! teachers and students.
My topic of this month is on the class of Biology.
The class is very cheerful but the subjet is difficult.
In class we study the cells , the organ sistem and the funcion(s) of this.
After we go to study the nourishment humanizes.
The class of Biology is bilingual. We speak in english but what we don't understand... we ask.
Now we are study the organ system:
- muscular.
- skeletal.
- nervous.
- endocrine.
- locomotor/muscoloskeletal.
- digestive.
- respiratory.
- urinary/excretory.
- circulatory.
- reproductive.

Riddles

I am a muscle
like music, I have a beat
What am I?


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