英语句子检查In the middle of the picture sit a multitude of people

In the middle of the picture sit a multitude of people,
改成:a multitude of people sit in the middle of the picture。
communicating with others by computer,which are used widely in mondern society。
改成:communicating with others by computers,
they pay more attention on the tools to contact lateral person。
改成they pay more attention to the tools contacting lateral persons(or people)。