We can take a look at the things people used in the past and some old pictures in _____.[ ]

A. the Great Wall

B. Wangfujing Street

C. the Palace Museum

D. Tian'anmen Square

下列哪些灭火方法属于直接灭火（）。

A.用水灭火

B.用砂子灭火

C.灭火器灭火

D.建造密闭