Good evening, here is the weather report. The weather tomorrow is vrey changeable. It will be sunny in the morning in Beijing. But in the afternoon, the weather will be rainy. In Shanghai, skies will be clear and you can enjoy the bright sunshine in the moning. But it will be clould with no sunshine in the afternoon. In Shenzhen , there will be a light right rain with winds in the morning, and in the after noon it will rain heavily.

1.It will be sunny in the morning in Beijing and      .

2.It will       in Beijing and Shenzhen tomorrow.

3.If you want to go to the park tomorrow in Beijing, you’d better go there in the      .

4.It will be       in the aftenoon in Shanghai.

5.It will be rainy and       in Shenzhen tomorrow.

某化学兴趣小组的同学准备用氢气燃烧法测定空气中氧气的体积分数，设计的实验装置如下图：

（1）写出仪器名称：A__________，D__________。

（2）甲中发生反应的化学方程式为：___________________________。

（3）实验时先检验氢气纯度，然后关闭开关C，打开开关B，点燃氢气并迅速插入乙装置中，直至火焰刚好熄灭时关闭B，冷却至室温后，下一步操作是__________________________________，在乙中观察到的实验现象是____________________，即达到实验目的。

（4）若将上图中的甲装置撤去，用CO气体代替氢气进行上述实验，实验能否达到同样目的？_______（填“能”或“不能”）。若能，说明理由；若不能，应如何改进？ ________________________。