根据句意及所给提示，补全单词或用单词、固定短语、固定搭配的正确形式填空。
1. ______(luck), by the time I got there,the bus had already left. I had to walk to school.
2. The bird is in i______ nest.
3. A q______ is another way of saying fifteen minutes.
4. On her ______ (二十) birthday, she received a lot of presents from her friends.
5. We ______ (花费) a long time looking for a public restroom yesterday.
