a film of oil的用法和样例：
- All over the ship the bulkheads sweated a film of oil and water.
- All over the ship the bulk heads sweated a film of oil and water.
- A film of mucus and bacteria on a tooth surface.
- It's a film of triangular love affair.
- A film of oil is inserted between the sliding surfaces of a bearing.
- The mirror is covered with a film of dust.