B, the liquid carbon dioxide fire extinguisher does not leave any trace after the fire, and will not cause damage to books and files, so it can be used to put out fires such as books and files, so the option is correct.
C, foam extinguisher can be used to put out common fires such as wood and cotton cloth, and the sprayed solution will damage books and archives, which is not suitable for putting out books and archives fires, and the choice is wrong.
D liquid oxygen can be used for combustion, but not for fire fighting in books and archives, so the option is wrong.
Therefore, choose: B.
I remember that the saying "if you are serious, you will lose" began to spread on the Internet five or six years ago. When I first heard this sente