某化学兴趣小组的学生从网上查得如下信息：①钠能在CO₂中燃烧．②常温下CO能与PdCl₂溶液反应得到黑色的Pd．经过分析讨论，他们认为钠在CO₂中燃烧时，还原产物可能是碳、也可能是CO；氧化产物可能是Na₂CO₃，为验证上述推断，他们设计如下方案进行实验，请回答下列问题：

（1）他们欲用上述仪器组装一套装置：用石灰石与盐酸反应制取CO₂（能随意控制反应的进行）来证明钠能在CO₂中燃烧、检验气态还原产物，所用仪器接口连接顺序为　____ ，制取CO₂反应的离子方程式为　____ 　

（2）装置连接好后，首先要进行的实验操作是____ ；点燃酒精灯前，应进行的操作是____ ；等装置____ 现象时，再点酒精灯，这步操作的目的是____ ．

（3）若仪器D中有黑色沉淀，C中残留固体（只有一种物质），则C中反应的化学方程式为____ ；若仪器D中溶液无黑色沉淀，C中残留固体（有两种物质），则C中反应的化学方程式为____ ．

填表：比较戚家军与岳家军的异同。

如图示关节的结构模式图，据图回答．（括号内填数字，横线上填文字）

    The Great Pyramid(金字塔)was built nearly 5,000 years ago for a king called Khufu. It is on the west bank of the Nile River. In fact, all the pyramids along the Nile River are on its west bank. The ancient Egyptians thought of the rising of the sun as the beginning of life and the setting of the sun as the end of life. This is why their bodies were buried on the west of the Nile.

    It is very hard to realize just how big the Great pyramid is. It has over 2,000,000 pieces of stones. Most of these big stones weigh two and a half tons each. Some even weigh fifteen tons. Without machinery, the ancient Egyptians cut and moved and lifted each of these stones. Almost all the stones came from the east bank of the Nile, and they were taken across the river in boat. It took more than 100,000 people twenty years to build the Great Pyramid.

    The Great Pyramid is over 450 feet high today. Each of the sides of the Pyramid is 755 feet long. It takes about twenty minutes to walk all the way around it.