Question

a student is riding on a school bus and suddenly get thrown forward. what did the bus just do? the bus makes a hard turn to the left. the bus makes a hard turn to the right. the bus is going forward and suddenly stops. the bus is going backward and suddenly stops.

Explanation:

When the bus is going forward and suddenly stops, due to inertia (an object's tendency to maintain its state of motion), the student who was in motion (moving forward with the bus) continues to move forward and thus gets thrown forward.
For a hard - turn (left or right), the student would be thrown to the side opposite to the turn direction (right for a left - turn and left for a right - turn). If the bus is going backward and stops, the student would be thrown backward.

Answer:

The bus is going forward and suddenly stops.