Question

1. a social networking site where people communicate through short updates called \tweets\. 2. a professional networking site. 3. the worlds largest social networking site that connects \friends\. 4. a social networking site made for sharing photos and videos from a smartphone.

Explanation:

1. Twitter is known for short - form communication via Tweets.
2. LinkedIn is a platform for professional networking.
3. Facebook is the largest social network for connecting friends.
4. Instagram is designed for sharing mobile - based photos and videos.

Answer:

1. Twitter
2. LinkedIn
3. Facebook
4. Instagram