在下列各句的空白处填入一个最恰当的单词，使句子意思完整，语法正确。

1. —Who does this backpack_____to?  

    —I think it's Lucy's.

2. I think Lu Xun is the greatest_____in China.  He wrote a lot of books.

3. I'm free tomorrow.  Let's take some food to go for a_____in the mountain.

4. The_____exam at the end of the term is quite important to you. You must do your best.

5. Do you know who is the_____of the car? It should be moved.

6. She is_____about her little son, because he is alone at home.

7. Our English teacher said that the spoken English test would make_____20% of the final     exam.