Step 1 : Introduction to the question "What do languages Arabic, Chinese, English, French, Russian and Spanish have in common?"
...In 1968, Russian was added as a working language of the General Assembly so that, of the GA's five official languages, four (all but Chinese) were working. ... As of 1983, the Security Council (like the General Assembly) recognized six official and working languages: Arabic, Chinese, English, French, Russian, and Spanish. The law says that “Chinese and English” are Hong Kong's official languages. Whereas some people say that Cantonese is a dialect of Chinese, others insist that it is a language in its own right. ... (The Mandarin Chinese term for Cantonese, Shanghaiese and others is fangyan, or “place-speech”.)
Step 2 : Answer to the question "What do languages Arabic, Chinese, English, French, Russian and Spanish have in common?"
Official languages of the United Nations:
The United Nations recognizes six official languages: Arabic, Chinese, English, French, Russian and Spanish. Delegates can speak in any of the official UN languages. Speeches given in one language are simultaneously interpreted into the other official languages. Providing a correct translation and interpretation of spoken and written communication is a major factor in the work of the UN. It enables clear, concise communication on the important issues this global body addresses. Source: UN.org