When you feel asneeze（喷嚏）or cough coming on, covering your mouth prevents the spread ofgerms(细菌). You probably knew that.

    But how to cover your mouth is very important. You might usetissues(纸巾), and put your used tissues into the bin. "If you don't have tissues, you should sneeze into your elbow, not your hand, even if you are used to doing that." The doctors advised.

    "If somebody sneezes into his hands, those germs will be passed on to other people, or other objects that people touch." said Dr. Hill.

    Germs are most commonly spread by sneezing and coughing. When they land on your hands, they are passed from hands to things like bills, doorknobs(扶手),elevator buttons（电梯按钮） and other surfaces. At the same time, the people around you can touch them.

This isn'tnagging（唠叨）. The Centers for Disease Control also suggest that sneezing and coughing into your elbow is necessary. Even the New York City subway officers ask the passengers to "cough or sneeze into elbow or use a tissue."

    "The suggestion was taken seriously about 10 years ago. However, most people didn't pay much attention to it. That means the adults may have missed the advice. But children are often taught in school the right way to cough or sneeze." Dr. Benjamin said.

    To be clear, people can't keep away from all the risks in this way, but it's the best choice. At the same time, we'd better wearmasks（口罩） and often wash our hands. "Hand washing is one of the most important things people can do to keep healthy." Dr. Hill said.