题目

反应3Fe(s)+4H2O(g) Fe3O4 (s)+4H2(g) ,在一个可变容积的密闭容器中进行,试回答:(1)增加Fe的量,其正反应速率的变化是__________(填“增大”“不变”或“减小”,以下相同)。(2)将容器的体积缩小一半,其正反应速率__________,逆反应速率__________。(3)保持体积不变,充入N2 使体系压强增大,其正反应速率__________,逆反应速率__________。(4)保持压强不变,充入N2使容器的体积增大,其正反应速率__________,逆反应速率__________。 Most people usually have less money at the end of the month than ____ at the beginning.     A. which is             B. which was           C. they have             D. it is