[Q]: The man had lipstick on his cheek.
What is the cause?

[A]: The woman kissed him.

[Q]: The boy tuned the radio.
What is the cause?

[A]: The station was coming in with static.

[Q]: The photo albums collected dust in the attic.
What is the cause?

[A]: They remained untouched for years.

[Q]: The computer crashed.
What is the cause?

[A]:
I downloaded a virus.