4NH₃（g）+3O₂（g） $\stackrel{催化剂}{\rightleftarrows }$ 2N₂（g）+6H₂O（g）　①

4NH₃（g）+5O₂（g） $\stackrel{催化剂}{\rightleftarrows }$ 4NO（g）+6H₂O（g）　②

下列描述可说明两反应均达到平衡的是（   ）

    Danny's father is a firefighter. He works at fire station. He's very brave. He h____ short yellow hair. He is tall and thin. His c____ are orange. He likes putting out the f____. Danny's mother is a t____. She works in a school. Her students like her very much. She has a b____ and two dresses. They are purple.

    They are nice. She likes playing games with her students. She is a good teacher.

利用大气压工作的是（　　）

____双