Sweden was the first country to recognize sign language as an official language in 1981.

American Sign Language (ASL) is the most common sign language in the world, with over 2 million users in the United States and Canada.

All of the above. Sign languages are used by deaf people, while gestures are used by hearing people. Sign languages are more complex than gestures and have a grammar, while gestures do not.

All of the above. Research helps to document and preserve sign languages, develop new sign languages, and improve the teaching of sign languages.

All of the above. Sign language research faces a number of challenges, including lack of funding, lack of access to deaf participants, and lack of qualified researchers.

All of the above. Sign language research can lead to improved understanding of sign languages, development of new sign languages, and improved teaching of sign languages.

All of the above. Sign language researchers must consider a number of ethical issues, including obtaining informed consent from deaf participants, protecting the privacy of deaf participants, and avoiding exploitation of deaf participants.

All of the above. Future directions of sign language research include development of new technologies for sign language communication, research on the cognitive and linguistic aspects of sign languages, and research on the history of sign languages.

The World Federation of the Deaf (WFD) is the international organization that promotes the use of sign languages.

The National Association of the Deaf (NAD) is the American organization that promotes the use of sign languages.

The British Deaf Association (BDA) is the British organization that promotes the use of sign languages.

The Canadian Association of the Deaf (CAD) is the Canadian organization that promotes the use of sign languages.

Deaf Australia is the Australian organization that promotes the use of sign languages.

The New Zealand Deaf Association is the New Zealand organization that promotes the use of sign languages.

DeafSA is the South African organization that promotes the use of sign languages.