教材中有一个演示实验：用脱脂棉包住约0.2g Na₂O₂粉末，置于石棉网上，可观察到脱脂棉燃烧起来．

（1）由实验现象能得出的有关Na₂O₂与水反应的结论是：a．有氧气生成；b．____ ．

（2）某研究性学习小组拟用如右图所示装置进行实验，以证明上述结论．

①用以验证结论a的实验方法及现象是____ ．

②用以验证结论b的实验方法及现象是____ 

对我们中学生来说，在家庭关系中，最主要的是（）

完形填空。通读下面的短文，根据短文内容，从 A、B、C 三个选 项中选出可以填入空白处的正确答案。

Long long ago, there was a beautiful little girl. She was 1because she had no family and no home. She only had her clothes and some bread. But she was very kind.

 A man asked her2she had something to eat. She gave him her3.

A child cried and told her that his 4was very cold. So she gave him her hat.

Then, she met a child with no coat. She gave him her coat.

One day, in the cold5forest, she met another child who

 6her dress. The little girl thought that it was dark and

7could see her, so she gave her dress away. At last, she had almost nothing: no family, nowhere to live, nothing to eat and little to wear.

8, stars fell from the sky. These stars became beautiful pieces of money. With the money, she9a new dress and a coat.

The little girl was rich for the10of her life and she still helped the people in need with her money.

羚羊在狂奔，长颈鹿伸着脖子吃树梢上的嫩枝绿叶，成群的斑玛向水草地迁移，凶猛的狮子和豹紧追其后，赶上落后的斑马，饱餐一顿．这种景观出现在（  ）