Is the statement 'The slope of a position-time graph can be negative' true or false?

In the picture shown,a ball starting from rest rolls down a ramp $AB$,moves along the horizontal bottom $BC$,then goes up a smaller ramp $CD$,and thereafter rolls on the horizontal plane $DE$. Ignore friction and air resistance. Which of the following figures shows the variation in speed with time?

The position of a particle related to time is given by $x = (5t^2 - 4t + 5) \, m$. The magnitude of velocity of the particle at $t = 2 \, s$ will be $........... \, ms^{-1}$.

The $v-t$ plot of a moving object is shown in the figure. The average velocity of the object during the first $10$ seconds is...........$m/s$.

The area under an acceleration-time graph gives:

$A$ particle moves along $X$-axis in such a way that its coordinate $x$ varies with time $t$ according to the equation $x = (2 - 5t + 6t^2) \ m$. The initial velocity of the particle is ....... $m/s$.