Fail microloader: development.js and testing.js

Can you explain to me why the files .sencha/microloader/development.js and .sencha/microloader/testing.js have the forward line in that way:

Code:

 write('< script src="'+path+'" > < /'+'script >');

I know that when it's running its has no problems, but I don't understand why contatenate in this way ('+'script). I don't see the usefulness of that.Thanks