Concept:A model rocket is made up of standard structural and safety parts. We are asked to identify which choice is not one of these parts.
Explanation:The body tube is the main frame of the rocket.
The nose cones reduce air resistance and protect the upper part of the rocket.
The fins help to stabilize the rocket during flight.
Recovery devices, like parachutes or streamers, are normally included for a safe landing.
However, the phrase “Not recovery devices” does not describe any actual part of the rocket.
It simply states that something is not a recovery device, so it cannot be a component of a model rocket.
Therefore, among the options, D is the correct choice.
Answer:D. Not recovery devices.