Across
- 3. A distinctive cloud that usually comes from an huge explosion
- 5. one of the first event that had sparked the attack on japan
- 6. The people that the US were ready to use a nuclear warhead against
- 7. US had done this after pearl harbor
Down
- 1. A research and development undertaking during WW2
- 2. A competition for supremacy in nuclear warfare
- 4. A war that had started on march 12,1947