Settings
Yes Deleting from your mac, frees up Hard drive space.
Press space bar
press the space bar
Select an icon with a single click and then press the space bar to activate a Quicklook window.
click on the bookmark and press back space
The Mac OS X Quick Look feature allows the user to preview a file by selecting it's icon with a single click and pressing the Space bar. Pressing the Space bar again will end the preview or, in common with many Mac OS X features, pressing the Escape key (esc in the top left corner of the keyboard) will also end a Quick Look preview.
The Option key (often labelled Alt) is found in the middle of the three keys either side of the Space bar; the three keys being from the outside moving towards the Space bar: Control (ctrl), Option (alt) and Command (cmd)
Press the three keys next to the space bar (Cmd, Alt, Ctrl) and the number 8.
Depends on what is wrong with it. If it is loose, you may be able to fix it by carefully attaching it. If it is okay mechanically but does not produce a space when typing, it probably needs to be very carefully removed and cleaned underneath.
The task bar.
You cannot.
No.