Given a scientific passage and an answer, generate a question for the given answer.

[EX Q]: Passage: Coal is the source of most electricity. Answer: coal
[EX A]: What is the source of most electricity?

[EX Q]: Passage: Types of neurons include sensory neurons, motor neurons, and interneurons. Answer: interneurons
[EX A]: Types of neurons include sensory neurons, motor neurons, and?

[EX Q]: Passage: An enveloped virus. Varicella zoster virus causes chicken pox and shingles. Answer: chicken pox and shingles
[EX A]:
Varicella zoster virus causes what two illnesses?