All of us know that breakfast is very ____ 'nesəsərɪ to us. It is____of the most important meals of the day. To keep ____ (health), everyone should have a good breakfast.____ (eat)the right food is good for our health. We can have eggs, bread, milk and other food ____ breakfast.

    Many students go to school without breakfast.____  bɪ'kɒz they get up late or their parents don't cook for them. It's ____ for their health.

    Without breakfast children may not____grəʊfast and may not study and play very well at school. They may be easier to get____(ill). And when they're ill, it will____(take) them a long time to recover（恢复）. I think everyone should have some good eating habits.

“保护环境，从我做起”，以下做法不利于环境保护的是（  ）

在HF、H₂O、NH₃、CH₄、CO₃^2﹣、CO₂、HI分子中

（1）CO₃^2﹣的价层电子对的空间构型为 ____

（2）以极性键相结合，具有正四面体结构的非极性分子是　 ____　．

（3）以极性键相结合，具有三角锥型结构的极性分子是　 ____　．

（4）以极性键相结合，具有V型结构的极性分子是　 ____　．

（5）以极性键相结合，而且分子极性最大的是 ____