What can you say about the motion of an object if its speed-time graph is a straight line parallel to the time axis?

The figure shows the distance-time graph of three objects $A$,$B$,and $C$. Study the graph and answer the following questions:
$(a)$ Which of the three is travelling the fastest?
$(b)$ Are all three ever at the same point on the road?
$(c)$ How far has $C$ travelled when $B$ passes $A$?
$(d)$ How far has $B$ travelled by the time it passes $C$?

The area under a $v-t$ graph represents a physical quantity which has the unit:

If the displacement-time graph for a particle is parallel to the displacement axis,what is the velocity of the particle?

The following table shows the position of Renu, while she is going to her school. Draw a distance-time graph for her motion.

Time	Distance from her home $(km)$
$06:45 \, am$	$0$
$07:00 \, am$	$8$
$01:30 \, pm$	$8$
$01:45 \, pm$	$0$

$A$ body moves with a velocity of $2\, m s^{-1}$ for $5\, s$,then its velocity increases uniformly to $10\, m s^{-1}$ in the next $5\, s$. Thereafter,its velocity begins to decrease at a uniform rate until it comes to rest after $5\, s$.
$(i)$ Plot a velocity-time graph for the motion of the body.
$(ii)$ From the graph,find the total distance covered by the body after $2\, s$ and $12\, s$.