The Open [Ctrl + O] 
button in the tab File of the menu activates the standard Open dialog box.
In the dialog box the way to the file is specified. In this window it is possible to perform preview of the drawing. To do that check the option Preview active under the area of preview, which is in the right part of the window. The dialog box Open also provides with the possibility to open several files simultaneously with the help of keys Ctrl and Shift.
The opened file is automatically added to the list of Last files.
To navigate through the drawing the mouse, the keyboard and scroll bars are used. With the help of the keyboard and the scroll bars the navigation is fulfilled only vertically or horizontally. The pointing device “Mouse” allows to fulfill navigation in any direction of the screen plane.