In this task, you're given an open-domain question. Your task is to provide an answer to the given question. There is only one unique answer for each question. Your answer should be short, and refer to an entity, date, number, etc. Do not put your answer in the context of a sentence.

Do zebras have white stripes or black stripes?
black and the white stripes and bellies are additions

When were the latest acm code of ethics and professional conduct adopted?
1992

In which stage of cognitive development does the conservation concept first appear?

Concrete operational stage