题目

完形填空（20 分） 阅读下面短文，掌握其大意，然后从下列各题所给的A、B、C和D四个选项中，选出最佳选项。 Many people of my generation(代，一代) say that there is no hope for the future because of the way that  11   people behave today. Their first argument（论点） is that when we were young we used to look after the   12   people in our community and help them. They also say that young people today don’t   13   about anything or anyone. However, I think the reason why we looked after older people was that we had no  14   . Peopl.在一定温度下，容器内某一反应中M、N的物质的量随反应时间变化的曲线如下图，下列表述中正确的是 A．反应的化学方程式为：2MN    B．t2时，正逆反应速率相等，达到平衡  C．t3时，正反应速率等于逆反应速率      D．t1时，N的浓度是M浓度的2倍