Answer:
Step-by-step explanation:
Before they went in they put on the breathing apparatus which was kept in the back of the fire engine. (adverbial clause)
who was the most experienced fireman (adjectival clause)
When he reached the back of the building, he noticed a metal door to a store cupboard which was firmly closed. (adverbial clause)
which was lying unconscious on the floor (adjectival clause)
so that he could carry him to safety (adverbial clause)