Do you know who invented light bulb?bulb要不要用复数?还有This chair is made of metal and wood.metal要不要用复数？
问题描述：
Do you know who invented light bulb?bulb要不要用复数?
还有This chair is made of metal and wood.metal要不要用复数？
答
不用
答
bulb不需要用复数.只是表示灯泡这种物体.例如：Edison invented the light bulb.
爱迪生发明了电灯泡.（金山词霸）
metal也不用,在这里只是表示某种材料.