根据下列句子的意思及所给的汉语提示，写出空缺处单词、固定短语或固定搭配的正确形式。

1. Do you know that some               （外国人）will come to our school?

2. Everyone in our class like the girl because she always talks to others           （礼貌地）

3. I will not buy that refrigerator because I have               （用完）money.

4. —Excuse me, how long may I               （借）this book?

—Ten days.

5. My uncle is so               （忙于）his new book that he looks so tired.