Are all the paired sentences grammatically correct? or do all those sound natural to native speakers

I am an English teacher who has a duty to teach correct English to the students who want to learn it. That is why I think I have to know grammatically correct English because it can destroy my students' lives if I teach them wrong or incorrect English. And one of my students asked me which of the two is correct or if both are correct. But for me, passive sentences sound unnatural, but I am not sure about that. That is why I am asking native speakers or grammarians which of the two is grammatically correct or which of the two sounds more natural to native speakers.

1.The car is too old to repair. =The car is so old that we cannot repair it.


2.The car is too old to be repaired. =The car is so old that it cannot be repaired.


3.The coffee is too hot to drink.
=The coffee is so hot that we cannot drink it.

4.The coffee is too hot to be drunk. =The coffee is so hot that it cannot be drunk.


5.Microbeads are too small to filter out during the waste water treatment process. =Microbeads are so small that we can not filter them out during the waste water treatment process


6.Microbeads are too small to be filtered out during the waste water treatment process. =Microbead are so small that they cannot be filtered out during the waste water treatment process.