a swan preening its feathers的用法和样例：
- The exquisitely furnished room was silent except for the rustle of the parrot in its cage as it preened its feathers.
- A swan has white feathers and a long thin neck.
- In this photo released by the Wildlife Conservation Society, a Chilean pink flamingo preens its feathers at the Bronx Zoo in New York, Wednesday, Sept. 10, 2008.
- The witch turned the princess into a swan.
- A bird preened its feathers.