沈括《梦溪笔谈》载：“世间锻铁所谓钢铁者，用柔铁屈盘之，乃以生铁陷其间，泥封炼之，锻令相入，谓之团钢。”这项技术最早出现于（    ）

读世界板块的分布图，回答：

关于图中板块的叙述，错误的是 （   ）

呼吸的全过程包括下面四个环节，其正确顺序是（　　）

①肺内气体交换  ②组织内气体交换  ③肺通气  ④气体在血液中的运输．

A

    Shanghai's Maglev Train(磁悬浮列车) runs from Longyang to Pudong International Airport(国际机场). The whole trip takes about 8 minutes.

    Children at or under 120 cm tall don't need to buy tickets to take the train, but they cannot take the train by themselves. Children above 124 cm must buy a full-price ticket.

    If you buy a round ticket, you can get on the train at Longyang Road Station or Pudong Airport Station, and get off at the other station. The return part of the ticket must be used on the same day.