31.[化学—物质结构与性质](13分)
(1)依据第2周期元素第一电离能的变化规律,参照右图B、F元素的位置,用小黑点标出C、N、O三种元素的相对位置。
参考答案:
解析:
城市规划规定了某宗土地的用途、建筑高度、容积率、建筑密度等,那么,对该宗土地进行估价就必须以其使用符合这些规定为前提。( )
Your vessel is equipped with a fixed C02 system and a fire main system. In the event of an electrical fire in the engine room what is the correct procedure for fighting the fire?().
A.Use the C02 system and evacuate the engine room
B.Use the fire main system and evacuate the engine room
C.Evacuate the engine room and use the C02 system
D.Evacuate the engine room and use the fire main system