单词拼写.

1. The Great wall is one of the seven________(奇迹) of the world.

2. She________(目标) to achieve her goal after two years.

3. The trip to Paris will be an________(理想的) opportunity to practice my French.

4. She always insists that her writing paper is of good________(质量).

5. As far as I know, he will________(退休) next month.

6. During the school holidays the children enjoyed their________(自由).

7. The supermarket opened last year sells a________(种类) of goods.

8. I have made a________(记号) on the map where we should go.

9. When four banks failed in one day, there was a________(惊慌) among businessmen.

10. That________(解释) for the delay of the train.

当把H2O（l）和D2O（l）混合后，会自发发生下面反应：H2O（l）+D2O（l）=2HOD（l），O-H键和O-D键的键焓几乎没有区别，那么这个反应的主要驱动力是（）。