题干
----I wonder how long you_________ in Hangzhou．
----Just for the weekend，then I had to attend a conference in Wuhan．
A：will stay
B：stayed
C：have stayed
D：were staying
答案(点此获取答案解析）
B
2N2(g)＋3H2O(g) ΔH<0 在恒容的密闭容器中，下列有关说法正确的是