Can you find the hidden subject of this message? Samples occur throughout the passage and there is a somewhat obvious clue included also.

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> I want to help teenagers to pass the science test.  
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>  To do this, I taught a lenient student  
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>  About carbon. Are a few things made from it?  
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>  Learning about carbon is not something to knock, even if you'd rather go to the spa.  
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>  You'd wonder, could a spa get teenagers more interested in science?
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> 
> 

I'm not 100% sure on what tags I should attach to the question, so I'll just mention that all that's required to solve this is simply to read it.