下列施工现场安全标志中,属于指令标志的是()。
A.佩戴安全帽标志
B.禁止通行标志
C.当心落物标志
D.安全通道标志
参考答案:A
Although I liked the appearance of the house, what really made me decide to buy it was the beautiful________ through the windows.
A.view
B.scene
C.sight
D.scenery
简述防火墙的基本功能。