In this section of the speech, the purpose of the parallel structure is to obama

Obama talks about different professions in the speech, they aren't just limited to science or writing. Also he is not saying that you should take specific classes, but rather you should try and do your best in every class, because you never know which class may provide you with inspiration or the skills you need later in life.

sing because that is what they are doing in the sentence

explanation:

the simple predicate is the main verb in the predicate that tells what the subject does. example: my father fixed the dryer. read each sentence. draw a line under the complete predicate.

to me i think class room sitting education is better. i do online school and i have not learned a think haha. when i sit in the classroom i just sit there and kind of pay attention but still i get so far ahead in the class when im doing online i have nothing else better to do but play video games and i sit in school and learn and have friends and just actually learn. when i'm doing online i sit here listing to music and get on and and look up the answers i guess that is my fault for being a cheater. but to be honest i think sitting in the classroom is better.