Question

were the \duck and cover\ drills, as promoted by civil defense initiatives, effective measures for protection?
no, but since the government had no idea how to address the nuclear threat, it created the impression that it had solutions to offer the people.
yes, because fabric had been proved to block the radioactive gamma rays, deflect the heat of the blast, and shield the body from fallout.
no, but conducting frequent nuclear attack drills helped limit public hysteria by keeping americans busy and reassured of potential survival.
yes, because the light from the flash of a nuclear detonation cannot penetrate solid objects to burn people crouched behind them.

Explanation:

The "duck and cover" drills were not truly effective against the full - scale threat of a nuclear explosion. However, they did serve a psychological purpose by keeping the public occupied and making them feel there was a survival strategy. Fabric could not block gamma rays, deflect blast heat or fully shield from fallout. And while solid objects could block the flash to some extent, it was not the main reason for the drill's limited "effectiveness". The government likely promoted them to give an impression of having a plan in the face of a nuclear threat it didn't fully understand.

Answer:

No, but conducting frequent nuclear attack drills helped limit public hysteria by keeping Americans busy and reassured of potential survival.