填空题
What often caused the forest fire?
Forest fires are often caused by broken glass or ______.
填空题
Who put out a big forest fire in California?
______ have put out a big forest fire in California.
填空题
What caused the forest fire in California?
It was a ______ that caused the fire.
填空题
What did the fireman notice at last?
He noticed the remains of a snake which was wound round the ______ wires.
填空题
How to describe the cause of the fire?
It was simple ______.