Do just one thing

We all know that not wearing shoes inside can go a long way in keeping our house clean, since shoes can drag in dirt, pesticides and even lead. But going barefoot can be a bad choice, too. Natural oils in our skin can leave deposits on the floors, which work like a magnet to attract dirt. The solution? Take off your shoes at the door and lay them on newspaper (which absorbs toxins); wear socks inside the house. Keep a tray of clean socks by the door to offer guests who come to visit.

In 1940, exiled Communist leader Leon Trotsky died a day after being wounded in an attack by a Stalinist agent at his house in Mexico City. Trotsky had been an influential politician in the early days of the Soviet Union, and was a founding member of the Politburo. He was expelled from the party and deported from the country after a power struggle with Joseph Stalin.

In 1944, the United States, Britain, the Soviet Union and China opened talks in Washington that helped pave the way for the establishment of the United Nations.