A sentence Vanity is a constant; people will only start shopping more sustainably when they can't afford not to. What does 'they can't afford not to' mean? Thank you very much!

"Even" in this sentence Solved.

A sentence The best way to ensure that the right side wins is to increase competition. This sentence is quoted from an article in which the author compared two different ways of running family companie but didn't give a conclusion which one is right. How to understand "the right side wins" ?

HELD in this sentence Scalia joined Sotomayor's broad ruling in another case that held police officers generally must try to get a warrant before forcing uncooperative drunken-driving suspects to submit to a blood test. What does "held" mean here? held police officers= policemen who hold a gun？

About a sentence The sun rises that looks beautiful. I suppose this sentence is grammatically correct, but I find it awkward to read. Will it be better to express that in another way?

help me In sentence ‘Until these issues are resolved, a technology of behavior will continue to be  rejected, and with it  possibly the only way to solve our problems.’ how to understand 'and with it possibly the only way to solve our problems'?

an expert on/in an expert on (or in ) economic Which one is correct? I also saw a phrase 'an expert at skating', is it right?

one phrase

Is the sentence correct? The number of the homeless will reach( will have reached) 19 million by the end of this decade. Are they both right?