Alongside the human genome, the human microbiome is a subject of increasing focus in research. The totality of all microbes that live in and on the human body evidently plays a much greater role in the emergence of disease than was previously thought.

The first one is widespread in toothpaste, where it is used to fight cavities – fluoride. The second one is something most of us consume too much of, in the form of table salt – chloride. Chlorine atoms are also present in countless kinds of plastics, in coolants, and in propellants.

Jaguar, piranha, açaí – all of these are words that originally entered English from South America. They are borrowed from Guaraní, one of several hundred indigenous languages that are still spoken today by millions in Latin America.