③. 通常作不可数名词的集体名词 无生命的集合名词作主语时，谓语动词常用单数形式。machinery(机械)，clothing(衣服)，luggage(行李)，furniture(家具)，equipment(设备)，jewelry(珠宝)等作主语时，谓语动词常用单数。 Warm clothing is necessary in cold climates. 气候寒冷的地区需要暖和的衣物。 All the furniture has been moved to another room. 所有家具已经被搬到另外一个房间里。 My luggage was sent by air.

一、以集合名词做主语的主谓一致问题