1 . Be it the flu or the coronavirus (冠状病毒), we can all take one basic step to keep ourselves healthy--wash our hands regularly. But how _________ would you be to know that the practice of handwashing was not always around? We can thank a_________   for this important practice: physician Ignaz Semmelweis.

It was 1846     _________   no one knew germs (病菌) existed. Semmelweis worked at the Vienna General Hospital _________ two parts.The hospital’s ward was so large that doctors and midwives (助产士) divided it in half. At the time, there was a major_________ in the ward.   Many of the patients contracted (感染) childbed fever, a   _________   disease, after giving birth.

While looking after the women, Semmelweis noticed something___________   The women in the doctors’ ward were more likely to catch the fever than the women__________   by the midwives. Semmelweis also knew that the doctors worked in the ward before operating_________ the women. Semmelweis came up with a theory: the doctors__________ the women with dirty particles (微粒) from dead bodies! To test his theory, he _________ doctors to wash their hands with chlorine (氯) before going to the ward.   The rate of death _________ significantly.

________ , the practice of washing hands did not become widespread.   Semmelweis’ theory could not explain why women who gave birth outside of hospitals still contracted childbed fever. Many doctors _________   to believe that they were “responsible” for the disease. As a result, the medical community cast doubt on the practice of washing hands.

Handwashing was finally officially adopted in the 1980s by the United States Centers for Disease Control and Prevention. They_________   handwashing as an important factor in preventing the spread of infections. Despite this, handwashing is only performed one-third to half as often as it should be.