Explanation:

Language across the curriculum refers to the use of language as a tool for learning in various subject areas. When a teacher uses lessons in Science and Social science to teach language, it can be considered as a language across the curriculum approach. This approach recognizes that language is not only taught in language classes but also in other subject areas.

1. Language as a Tool for Learning:
In this approach, language is seen as a means of understanding and communicating ideas in different disciplines. It is used as a tool for learning and expressing knowledge in subjects like Science and Social science. Students are encouraged to use language to analyze, evaluate, and communicate information related to these subjects.

2. Integration of Language and Content:
Language across the curriculum approach integrates language skills with the content of different subjects. For example, in a Science class, students may be asked to read scientific texts, write lab reports, and engage in discussions using scientific vocabulary. Similarly, in a Social science class, students may read historical documents, write essays, and participate in debates using subject-specific language.

3. Developing Language Skills:
By using Science and Social science lessons to teach language, students have the opportunity to develop their language skills in a meaningful context. They learn subject-specific vocabulary, improve their reading comprehension, enhance their writing skills, and develop oral communication skills through discussions and presentations.

4. Authentic Learning Experiences:
Language across the curriculum approach provides students with authentic learning experiences. They are exposed to real-life situations where they need to use language effectively to understand and communicate ideas. This approach helps students see the relevance of language skills in different disciplines and promotes a deeper understanding of the content.

5. Holistic Approach to Education:
Language across the curriculum approach promotes a holistic approach to education. It recognizes that language is not separate from content knowledge but is intertwined with it. By integrating language and content, students develop a deeper understanding of both language and the subject matter.

In conclusion, when a teacher uses lessons in Science and Social science to teach language, it can be termed as a language across the curriculum approach. This approach integrates language skills with the content of different subjects, providing students with authentic learning experiences and promoting a holistic approach to education.