Question

The teacher was out of the classroom.the children made a lot of noise. Combine the following pairs of sentences without using and,but,so.

Answer 1

The children made a lot of noise because the teacher was out of the classroom

Answer 2

The statement after joining is following – As the teacher was out of the classroom, the children made a lot of noise.

The joining of sentence is required to join two or more simple sentences in a meaningful way.

That kind of sentence is known as Compound sentence.  It may have many co-ordinate clauses.