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　　Everyone knows the advantages of using email．It's much faster than ordinary mail．It's much cheaper than the telephone．However it is not always good to use email at work．

　　One reason is that email is only one-way．You send out your message and then you have to wait for an answer．This is not a problem if you need to send simple information．But if the message is more complicated email is not so good．In that case it's better to talk on the phone．Or if you're in the same building you should go meet in person．Then you can also take a little walk and you can get to know each other better．

　　There is another problem with email：You don't get much information from the message．You have only the words themselves．This doesn't matter if the messages is just about facts or if it is not important．But it might cause trouble if the message is about something important．You can't tell much about the person who sent the message．You have no idea what she was thinking or feeling．You may put your own feelings into the message．And this can lead to communication problems in a company．

　　In England psychologists(心理学家)did some research about using email at work．They studied office workers opening their email．The psychologists measured the blood pressure(血压)of the workers．They found that blood pressure went up if the messages seemed angry or negative(消极的)．It also went up if the messages were from the boss．It went up the highest when the messages were both negative and from the boss．

　　The psychologists said that people should be careful how they use email at work especially shoes with jobs in a company．Their messages can easily hurt or upset(使心烦)people．So never send important news by email．Try to meet face to face with the person．Then everyone will understand each other better and will work together better．

1．Is it a problem to send simple messages by email?

2．What was the psychologists' research about?

3．When did the office workers' blood pressure go up the highest?

4．Why should people be careful about using email according to the psychologists?

5．What does the writer mainly tell us in the passage?