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.
