根据短文理解，从A、B、C、D四个选项中选择最佳答案填空。

    English people usually spend more time with friends in public places like parks or pubs. They would not 1 others to their homes. You could work with a person or live next to someone for several years，but you could never see him 2 home.

    If someone invites you to his or her home, you'd better bring something 3 or eat, such as a bottle of wine or a box of chocolates. You can do so if you're invited to an American home. 4 with each other, they are almost the same.

    Once inside the house, the rules change again. Don't ask to see 5 what the English people show you. Never ask how much their house or any of things in it costs. The Americans, 6 may be glad to show you 7 their house. They will be pleased when you show your 8 and ask how expensive something is.

    English and American people will both have a drink or two before the meal. When you begin to eat, you should say how tasty the food is and ask something about it. Remember, never eat with your mouth 9 and make any noise while you eat. It is 10 to be impolite.

材料二：近年来，广东中小企业贷款在总贷款的余额中只占20％左右，扩大再生产所需资金严重不足。中小企业老板具有大专及以上学历的人只有10％，初、高中水平的人居多。

右图表示反应X（g）4Y（g）+Z（g），△H＜0，在某温度时X的浓度随时间变化的曲线：

下列有关该反应的描述正确的是（　　）