a piece of ribbon的用法和样例：
- The old man wears an eyeglass attached to a piece of ribbon.
- The old man wore an eyeglass attached to a piece of ribbon.
- I need a piece of string to tie this parcel up.
- She was hit by a piece of falling masonry.
- The boy is daubing a piece of paper with red ink.
- Would you please give me a piece of paper?