A、B、C是三种常见的含钙化合物．它们之间有如图所示的转化关系（部分产物略去）：

（1）A物质的化学式是____ ，B物质的俗称是____ .

（2）举出B物质在农业生产中的一种用途：____．

（3）反应③的化学方程式为　____ ，该反应的基本反应类型是____ ．

下列活动会对土壤造成破坏的是（   ）。

完形填空
      It's a fine Sunday morning. The weather is1. A lot of children2 in the park. They are3 happily. Some are playing4 under a big tree. Some girls are singing and dancing. Some boys are running5 the hill. Li Lei is6by the lake. He's reading a story. 7 is Wang Lin? He's standing over there. 8is he doing? He's looking9 a nice butterfly（蝴蝶）. He10to catch (捉住) it. 

— Excuse me, are there any book stores around here?

—      , but there are some on the Center Street.