吸烟有害健康．吸烟时产生一种能与人体血液中的血红蛋白结合的有毒气体是（　　）

阅读理解

B

      A father sat at his desk thinking of his poor family life when his young son ran in and said happily, “Dad, because this is your birthday and you’re 50 years old, I’m going to give you 50 kisses, one for each year!” But the father said, “Oh, Andrew, don’t do it now. I’m too busy!” Hearing this, the boy said nothing as tears (眼泪) ran down in his big blue eyes. The father felt sorry for his son, and then he said, “You can finish later.”

      The boy walked away, with disappointment on his face. That evening the father said, “Come and finish the kisses now, Andrew!” But the boy didn’t answer.

      Unluckily, a few days later, the boy had an accident (事故) and left his father forever.

      Love is a two-way street. We must warmly accept (接受) any loving act, or we will feel sorry.

宋元时期，封建经济继续发展。阅读下列材料，回答问题。

材料一：两宋时期，“国家的财政收入约80％来自淮河以南地区”，“国家根本，仰给东南”；“丝、棉纺织业、造纸业中心及对外贸易港口多集中在南方”；“苏湖熟，天下足”。

材料二：宋代时期，中外交往主要依靠海路，那时海外贸易兴盛，政府鼓励海外贸易，收入颇丰，以至于宋高宗说：“司舶之利最厚，若措施得宜，所得动以百万计。”

材料三：

请回答：