Nooneunderstoodcholeraandeverytimeitcame,thousandsdied....
問題詳情：Nooneunderstoodcholeraandeverytimeitcame,thousandsdied.Neitheritscause61.______itscurewasunderstood.QueenVictoria'sdoctor,JohnSnow,wantedtofind62.______howitwascaused.WhenthediseasecametoLond...