a thumbnail sketch的用法和样例：
- The novelist only gave a thumbnail sketch of his characters.
- The writer only gave a thumbnail sketch of his characters.
- Celinda Lake, an opinion pollster in Washington DC who carries out work for the Democrats, has a thumbnail sketch of that swing female voter.
- Since this was only a thumbnail sketch, today were going to look more carefully at the breakdown in living expenses
- Of, relating to, or of the size of a thumbnail.
- Select a thumbnail or icon to view its options.