The two more commons way of text alignment: Left vs. Justified alignment. What´s your preference?
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Cos the spacing makes it easier to read, and the lines have equal length, giving the text an even beautiful look.
0 
1 Consistent text look is easier to read
0 1 I’m not sure, but it seems more even than the left alignment. Maybe, if the left alignment example had some more balance with the ending lines.
By balanced, I mean on lines almost hits the edge while the other edge recedes and it alternates, but that’s not exactly possible without a lot of work…
0 1 Neat and clean!
0 1 It is just a question of symmetry. There is beauty and order in it. To me, the lack of alignment in a text indicates that the person writing is somewhat slovenly and disorganised, or the text is a draft and not the final thing.
1 1 Looks so much better.
0 1 
10-25-2008 | 5:34 am
Because there’s no ugly extra and uneven space, and it allows for easier and better scanning of text because the size of each line is relatively different.
3-2-2009 | 6:16 pm
Simple: It’s easier to read.
4-29-2009 | 4:06 pm
Easier to read. Don’t have to double-check for funny-spaced lines or bad hyphenation.
6-21-2009 | 8:27 pm
My eyes know where is the next word supposed to be.
10-26-2009 | 10:56 am
when left is preferable over justified
11-3-2010 | 4:08 pm
Nicer and more professional