Science fact today

* The structure of DNA was first proposed by James D. Watson and Francis Crick in 1953. * Thermistor is an instrument whose resistance varies with temperature. * A fully-grown female roundworm can lay about 200,000 eggs a day. * About 60% of the Earth's crust is made up of feldspars (a group of tectosilicate minerals). * Rüppell's Vulture is the highest flying bird in the world. It can fly at an altitude of 11,000 metres above sea level.