Translate please, i’d be able to help better:)
Answer:
Position-Time graphs display the motion of a object by showing the changes of velocity with respect to time.
The motion of a car on a position-time graph that is represented with a horizontal line indicates that the car has stopped moving.
A straight line with a positive slope indicates that the car is moving at a constant velocity, and thus the slope is constant. On the other hand, a curve with a changing slope, shows that the velocity is changing.
Answer:
has units of distance
has units of distance over time
has units of distance over 
has units of distance over 
Explanation:
Since the expression for the distance is:

then:
has units of distance
has units of distance over time
has units of distance over 
has units of distance over 
because we are supposed to be able to add all of the terms and get a distance. So the products on each term that contains factors of time (t) should be cancelling those time units with units in the denominator of the multiplicative constant s that accompany them.