a rag of cloud的用法和样例：
- There was not a rag of decency about him.
- Unheeded he kept by them as they came towards the drier sand, a rag of wolf's tongue redpanting from his jaws.
- I threw that piece of shit around like a rag doll.
- A dark bank of cloud loomed on the horizon.
- There is not a rag to cover him.