If it possible for an object to move for 10 seconds at a high speed and end up with an average velocity of zero? true or false

It's true and possible.  Velocity over a period of time depends on the displacement during that time.  Displacement is measured between the start point and end point.  If, say, you're moving along a circular track, and you stop when you reach the point where you started from, your displacement is zero, so your average velocity for the trip around the circle would be zero.

root word, prefixes, and suffixes

the best answer for these questions would be:

1.            c. is smaller

2.            d) concrete operational

3.            b) interaction with the environment – the children interact with their environment can them learn more.

4.            a) parents who reason openly with children can limit a child’s cognitive ability.