Hard to answer - you don't say where the duplicated line might be.
only if it is moved parallel to its original direction
Multiplying a function by -1 will make it a reflection of the original function across the x axis.
The mass remain unchanged.
No. You phones apps will remain seemingly unchanged. This udate is particularly harmless for those already running iOS 5 or iOS 5.0.1
the south can be racist.
The system remain unchanged.
yes
The color remain unchanged.
The mass remain unchanged.
The mass remain unchanged.
In theory, they can remain unchanged for their entire existence. However, in practise, nature isn't so nice and evolution happens eventually.
The mass remain unchanged; this is the law of mass conservation.