Suddenly _____ fire broke out in the room and everything in it was soon on. _____ fire.

A．He couldn’t decide on a topic for his paper.
B．He thought his paper was late.
C．He hadn’t heard from his family in a while.
D．He thought the woman had been ill.

A．To produce a gas containing carbon and hydrogen.
B．To remove impurities from methanol.
C．To heat the reactors.
D．To prevent dangerous gases from forming.