I don't mean to sound arrogant in any way but just to let you know these questions are way too easy. It's usually better to ask more open ended questions instead of it sounding like a quiz on JavaScript fundamentals
"What is the event loop?"
"It's how JS does async"
"How does it work?"
"There's a stack and a queue managed by the platform"
"How else could you design that?"
"Other languages have threads"
"What are the tradeoffs between evented I/O and threads?"
"Memory safety and programmer error, CPU/memory utilization"
...