Controls: Completely reconstructible system?

Consider the following model of a car, where v(t) is the speed and θ(t) is the throttle
angle

v(dot) ̇= -av+bθ

where a and b are positive constants. Now express the model in state space form with the states as position and velocity, assuming the measured output is the velocity. Is (A,C) completely reconstructible? Interpret your answer.

This is a confusing area of controls for me. Any help would be greatly appreciated, thanks!