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.
The answer is going to be false
Both flossing and brushing, of the teeth, are going to help one maintain strong teeth and healthy gums.
Teacher, coach, childcare worker, and physical trainer