问题补充：
If you’re in Florence, Italy and see a man on a ladder the dust off statues and buildings, don’t worry. It’s just Alessandro Ricci material for his famous smog painting.
A. wipe; accumulating
B. to wipe; to accumulate
C. wiping; gathering
D. wipes; to gather
答案：
A. wipe; accumulating
B. to wipe; to accumulate
(答案→)C. wiping; gathering
D. wipes; to gather
解析：考查非谓语动词的用法：句意：如果你在意大利的佛罗伦萨看见一个人在梯子上正擦去雕像和大楼的灰尘，不要担心这只是亚历桑德罗·里奇为他著名的烟雾绘画收集材料。第一空填wiping，使用see sb doing“看见某人正在做”，第二空填gathering“收集，聚集”，是现在分词做定语，accumulate是“累积”，选C。
