Every Friday afternoon our class walks down to the science (11) on the ground floor. Last week we heated water in three metal pots of different colors to see which one cooled down fastest. Our teacher asked us to (12) the temperature every two minutes and write it down. Nobody was allowed to guess. At the end of the hour the black pot had lost the most heat, exactly as the (13) in our textbook predicted. Mr. Lin says a good (14) is one that anyone else can repeat and get the same result, because a single lucky answer is not (15).
Marie Curie is remembered as the first person to win a Nobel Prize twice, once in physics and once in (16). She worked for years in a cold shed with poor equipment, and she had to (17) most of her own tools. Her notebooks are still kept in a lead box, because they are not yet safe to touch. She never took out a patent on her methods and earned little money from her greatest (18). Her careful notes, however, later gave a young (19) the (20) he needed to explain how energy leaves an atom.