The answer is 50%.
From the 'National Affairs' website, they conducted a study where they found that less than 20% of couples who married in 1950 ended up divorced, about 50% of couples who married in 1970 did.
And in regards to the basic unit of society question; the answer would be family. Family is the basic unit of society as it forms community and is the nucleus of civilisation.
Heart disease ways you can keep your heart healthy would be one.
1. Manners
2. Peer pressure
3. Sibling
4. Prejudice
5. Discipline
6. Cliques