用所给单词的适当形式填空.
1. The bookstore is very _____ (crowd) on Sundays, many students are reading in it.
2. The flowers sold in the supermarket are quite _____ (beauty).
3. They didn't make a _____ (decide) where to go.
4. After three _____ (hour) walk, he was too tired to go on.
5. Jim prefers reading to _____ (sing).