The underscore.
But actually you can use spaces in file names, in many file managers. I think it just shows you a space while it actually saves an underscore, or something like this.
<span>This is called an unshielded twisted pair cable, which is also known as a UTP cable. This type of cable has four pairs of wires that are twisted around each other. Because the wires are like this, the electrical interference is reduced.</span>
Use ctrl + or - or if in microsoft word, use the zoom tool
