任务型阅读。

     Dragon (龙) Boat Festival is coming near, which is celebrated every year on May 5th in the lunar

calendar (农历). This festival was started 2 000 years ago with a number of stories explaining its origin

(来源). The best - known story is about one of Chiese greatest poets (诗人) named Qu Yuan who lost

his life in the river on the fifth day of the fifth lunar month. People commemorate (纪念) Qu Yuan through

dragon boat races, eating zongzi and several other activities. The dragon boat race is the most exciting part of the festival.

     Dragon Boat Festival is regarded as one of the traditional festivals throughout China.

同义句转换，每空一词。

1. Dragon Boat Festival is regarded as one of the traditional festrvals around China.

    Dragon Boat Festival is regarded as one of the traditional festivals _____ _____China.

根据短文内容简答问题。

2. What is the most exciting part of Dragon Boat Festival?

                                                                            .

某学生往一支试管里按一定次序分别加入下列几种物质：

A．KI溶液，

B．淀粉溶液，

C．NaOH溶液，

D．氯水。发现溶液颜色按下面次序变化：①无色―→②棕黄色―→③蓝色―→④无色。

依据溶液颜色的变化回答下列问题：

（1）加入以上药品的顺序是_________________________________________________。

（2）写出①→②的离子反应方程式，若为氧化还原反应，请标明电子转移的方向和总数：_______________________________________________________________________。

（3）写出③→④的化学反应方程式：___________________________________________。