题干
—May I speak to Mrs. Smith?
—________Here we don’t have such a lady now.
A：Hold on，please.
B：Sorry，but she is out at the present.
C：Wrong number，sir.
D：Who is that speaking?
答案(点此获取答案解析）
C
等于
4NO (g)+6H2O(g)是工业制备硝酸的重要反应，此反应在10L密闭容器中进行，半分钟后，水蒸气的物质的量增加了0.45mol，则此时间内，若用NO的浓度变化来表示此反应的速率，则v（NO）应为