题目

The Piccadilly line to Heathrow (伦敦西斯罗机场) is not only the fast way to travel but also the cheapest. So the next time you’re flying to Heathrow, make sure you fly Piccadilly line. Your Piccadilly flight features (特点): l       Departures (发车) from 36 stops on the Piccadilly line, or from over 200 stations only one change way l       Service every 5 minutes to and from Heathrow throughout the day l       Journeys from central London taking less than 50 minutes l       Only £3.70 for a single adult fare (费用) l       See tables below f对可逆反应4NH3(g)+5O2(g) 4NO(g)+6H2O(g),下列叙述正确的是（    ） A．达到化学平衡时,4v正(O2)=5v逆(NO) B．若单位时间内生成xmolNO的同时,消耗xmolNH3,则反应达到平衡状态 C．达到化学平衡时,若增加容器体积,则正反应速率减小,逆反应速率增大 D．化学反应速率关系是2v正(NH3)=3v正(H2O)