Join the following sentences to make one complete sentence without using and, but or so.
The children were delighted. The exams had been cancelled.
Topic: Synthesis — clause of reason
Answer
The children were delighted because the exams had been cancelled. (Also acceptable: The children were delighted at the cancellation of the exams.)
The relationship is CAUSE AND EFFECT, and the DIRECTION matters: the cancellation is the reason for the delight, not the other way round. So BECAUSE, AS or SINCE introduces the exam clause.
Note the TENSES. "Were delighted" is simple past; "had been cancelled" is past perfect, because the cancellation happened BEFORE the delight. Both must be kept exactly as the original has them — a combined sentence changes structure, never tense.
The phrase version ("delighted AT the cancellation") is neater and avoids a conjunction altogether, which is exactly what the instruction asks for. Note the preposition: delighted AT an event, delighted WITH a thing, delighted BY a person’s action.