Final answer:
The references provided don't mention Kevin and Joules, but examples of technologies used to combat extreme threats include hydrogen balls for anti-gravity vehicles, advanced missile technology, radar systems, and early artificial intelligence.
Step-by-step explanation:
In the provided references, Kevin and Joules, or characters in similar scenarios, are not specifically mentioned. However, we can discuss the general theme of fighting aliens based on the excerpts from other characters and contexts.
Sister Sara in the first passage creates an air-car equipped with hydrogen balls to counteract gravity and wing-like blades powered by electricity to achieve flight. In the second excerpt, John and Kismine are faced with the threat of aviators who could potentially kill them, implying the need for a quick escape rather than a combative solution.
The last passage focuses on the Cold War, highlighting advancements in technology such as missile technology, radar systems, and the development of computers capable of reacting faster than humans with a nod towards artificial intelligence - elements that could conceivably be repurposed to combat alien threats in a speculative context