What three language were adopted by the DBTG?

The DBTG (Data Base Task Group) did not "adopt" languages in the way you might be thinking. They were focused on the standardization of database management systems, not on specific programming languages.

However, the DBTG's work was very influential in the development of several database languages, specifically:

1. Data Definition Language (DDL): Used to define the structure of a database, including tables, columns, data types, and relationships.

2. Data Manipulation Language (DML): Used to interact with data stored in the database, including adding, deleting, modifying, and retrieving data.

3. Data Control Language (DCL): Used to manage security and access control for the database.

The DBTG's work laid the foundation for the SQL language, which is now the most widely used database language. While SQL wasn't adopted by the DBTG directly, it reflects the ideas and concepts that the DBTG advocated for.

Therefore, it's more accurate to say that the DBTG's work influenced the development of DDL, DML, and DCL concepts that are fundamental to database languages like SQL.