of means they have average intelligence or better. Get by means to achieve something but just barely. Example "Did you do well on your test?" "I got by." The first sentence means "I am a person who normally does good things. I used think the reason children today don't achieve academically on drugs, divorces, and anything else that could distract them or keep them from achieving."

My opinion : The teacher is talking to the students in his/her class. And the teacher is basically saying to the students... she is the one trying to help you, and before she started teaching that class, she blamed the poor learning skills that the children have nowadays on drugs, divorce, etc..., because all of that kind of stuff distracts the children from trying to do well in school/learning. But I also believe she is somewhat hiddenly saying that the teachers are partially the blame too, because the teachers need to put more effort into helping the children learn. (and that's probably what inspired her to become a teacher). And one defined meaning of the expression "getting by/passing by" would be easier to try to explain in a circumstance. Example of a sentence : The students are barely "getting by/passing by" as they are making it through the school/learning system, etc... meaning that they aren't failing but they are barely passing(they could/should be doing alot better) as they make it through to new grade levels, etc.... Another example would be if your job doesn't pay that well, so you are barely making it through(barely getting by/passing by) in life..... meaning you have a roof over your head and food on the table, but you can't just go and do all the things that you want to do, because you are barely capable of just being able to pay your bills and buying the things that you have to have in life, so you can't afford to go out and buy all the things that you want, or do all the things you want to do, etc... And I'm sorry, but I don't know what "impediment" means, so I just went by what the rest of the sentence said to me. Hope this helps you in learning. Good luck :)