If you had to choose the single most important ___________(discover) of the 20th century, you would have a real
_________ on your hands. In just 100 years, the world changed completely. Amazing discoveries were made in medicine, communications and transport, not to
____________ our knowledge of the world and space. Medical advances
________ from discovering the causes of diseases under microscopes to surgical procedures
____________(replace)
__________(disease) organs with
________ (donate) ones. Communications changed
______ the introduction of mobile phones and the way we _
_________(通信) went
________ writing letters to emailing. We started flying around the world and
____________(同时), scientists figured
________ how to
______(劈开) the atom,
________(过去) thought to be the smallest particle of matter
______ the universe.