Some students in the use of jupyter notebook, but the compiler can not write code problems.
One reason for this may be that the server is not connected successfully.
Usually draw circles show where the wood has a successful connection.
At this point is the need to reconnect and re-open jupyter notebook. Haha
One is the right way to open jupyter use cmd command to open the command box direct input jupyter notebook on it. This method is generally unsuccessful connection to the server does not appear.
Question two:
this is not the case, there may be denied access to this kind of problem later with jupyter notebook opened directly operated.
Therefore, the recommended use cmd command to open the jupyter.