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学校新到一批理、化、生实验器材需要整理,若实验管理员李老师一人单独整理需要40分钟完成,现在李老师与工人王师傅共同整理20分钟后,李老师因事外出,王师傅再单独整理了20分钟才完成任务.
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    A blocked airway(呼吸道) can kill someone in three to four minutes, but it can take more than eight minutes for an ambulance to arrive. So a simple procedure such as opening someone's airway can save their life while they're waiting for emergency medical help. This means you're more likely to give first aid to someone you know than a stranger.

    There are many misconceptions (误解) surrounding first aid. Below are the ‘most popular' ones with details of what you should do.

    You should put butter or cream on a burn. The only thing you should put on a burn is cold water — keep the butter for cooking. Put the affected area under cold running water for at least ten minutes.

    The best way to treat bleeding is to put the wound under a tap. If you put a bleeding wound under a tap you wash away the body's clotting agents(凝血剂) and make it bleed more. Instead put pressure on the wound with whatever is available to stop or slow down the flow of blood. As soon as possible call 999. Keep pressure on the wound until help arrives.

    Nosebleeds are best treated by putting the head back. If you put the head back during a nosebleed, all the blood goes down the back of the airway. Instead advise them to tilt(倾斜) their head forwards and ask the person to pinch(捏) the end of their nose and breathe through their mouth.

    You need lots of training to do first aid. You don't — what you mostly need is common sense. You can learn enough first aid in a few minutes to save someone's life — whether it's from a book, attending a course or watching videos online.

    Remember: anyone can save a life