In accordance with the RA law "On Ensuring Road Safety" , a trailer (semi-trailer) is
Any mechanical vehicle that is towed by a rigid coupling.
2. Any vehicle not equipped with an engine which is intended to be driven as a single unit in conjunction with a motor vehicle (including special attachment).✓Respuesta correcta
Explicación
A trailer or semi-trailer is a vehicle without its own engine that is designed to operate as a unit with a motor vehicle, including a special attachment. Defining it as a mechanical vehicle towed only by a rigid coupling is too narrow about the connection and wrong about the presence of an engine.